Presenting information on a map

1. A method performed by a data processing apparatus to display, on interactive geographical maps indicating points of interest, heat areas comprising one or more bounded areas of the interactive map having at least a threshold heat intensity indicating a quantity of points of interest and having at least a minimum number of hotels, comprising, using one or more computing devices:

identifying points of interest within a geographical region, wherein identifying points of interest within the geographic region comprises:

obtaining a plurality of geotagged photographs, wherein each of the geotagged photographs is geotagged with a location;

for each of the plurality of geotagged photographs,

classifying the geotagged photograph as a tourist photograph if a user took the geotagged photograph during a specified time interval and the user has not taken any photographs in the geographic region outside of the specified time interval; and

classifying the geotagged photograph as a local photograph if the geotagged photograph is not classified as a tourist photograph;

classifying one or more locations as tourist points of interest based on a number of tourist photographs geotagged with the locations;

displaying, via a client computing device, a map for the geographical region at a particular zoom level, wherein the map at the particular zoom level comprises a plurality of map tiles;

constructing one or more heat areas for the displayed map using the identified points of interest, wherein constructing the one or more heat areas comprises assigning a corresponding heat intensity to each map tile of the plurality of map tiles based at least in part on a number of points of interest contained in the map tile at the particular zoom level;

determining one or more bounded areas of the map that (i) contain at least a minimum number of hotels, wherein the minimum number of hotels is at least two and (ii) have a heat intensity indicating a number of points of interest that exceeds a threshold heat intensity;

displaying, via the client computing device, one or more boundaries on the map, wherein each boundary encompasses at least a portion of the respective one of the one or more bounded areas of the map that (i) contain at least the minimum number of hotels and (ii) have a heat intensity indicating a number of points of interest that exceeds the threshold heat intensity.

2. The method of claim 1 wherein a point of interest is determined using business classification data.

3. The method of claim 1 wherein the one or more bounded areas are determined using a linear regression method.

4. The method of claim 1 wherein the one or more bounded areas are determined using a convex hull method.

5. The method of claim 1 wherein the one or more bounded areas are determined using a connected cell method.

6. The method of claim 1 , wherein assigning a corresponding heat intensity to each map tile of the plurality of map tiles comprises:

assigning, using the one or more computing devices, a respective heat value to each corner of the map tile; and

applying, using the one or more computing devices, a smoothing function to the heat values assigned to the corners of the map tiles to assign the heat intensities for the plurality of map tiles.

7. A system to display, on interactive geographical maps indicating points of interest, heat areas comprising one or more bounded areas of the interactive map having at least a threshold heat intensity indicating a quantity of points of interest and having at least a minimum number of hotels, comprising:

a storage device; and

a processor communicatively coupled to the storage device, wherein the processor executes computer-executable program instructions that are stored in the storage device to cause the system to:

identify points of interest within a geographical region, wherein identifying points of interest within the geographic region comprises:

obtaining a plurality of geotagged photographs, wherein each of the geotagged photographs is geotagged with a location;

for each of the plurality of geotagged photographs,

classifying the geotagged photograph as a tourist photograph if a user took the geotagged photograph during a specified time interval and the user has not taken any photographs in the geographic region outside of the specified time interval; and

classifying the geotagged photograph as a local photograph if the geotagged photograph is not classified as a tourist photograph;

classifying one or more locations as tourist points of interest based on a number of tourist photographs geotagged with the locations;

display, via a client computing device, a map for the geographical region at a particular zoom level, wherein the map at the particular zoom level comprises a plurality of map tiles;

construct one or more heat areas for the map using the identified points of interest, wherein constructing the one or more heat areas comprises assigning a corresponding heat intensity to each map tile of the plurality of map tiles based at least in part on a number of points of interest contained in the map tile at the particular zoom level;

determine one or more polygonal areas of the map that (i) contain at least a minimum number of hotels, wherein the minimum number of hotels is at least two, and (ii) have a heat intensity indicating a number of points of interest that exceeds a threshold heat intensity;

display via the client computing device, one or more boundaries on the map, wherein each boundary encompasses at least a portion of the respective one of the one or more bounded areas of the map that (i) contain at least the minimum number of hotels and (ii) have a heat intensity indicating a number of points of interest that exceeds the threshold heat intensity.

8. The system of claim 7 wherein a point of interest is determined using business classification data.

9. The system of claim 7 , wherein the bounded areas are determined using a linear regression method.

10. The system of claim 7 , wherein the bounded areas are determined using a convex hull method.

11. The system of claim 7 , wherein the bounded areas are determined using a connected hull method.

12. The system of claim 7 , wherein classifying each of the plurality of geotagged photographs as either a tourist photograph or a local photograph comprises:

determining that the geotagged photograph is a tourist photograph when a user took the geotagged photograph during a specified time interval and the user has not taken any photographs in the geographic region outside of the specified time interval.

13. The system of claim 7 , wherein assigning a corresponding heat intensity to each map tile of the plurality of map tiles is based at least in part on a number of tourist photographs geotagged with locations in the map tile.

14. A computer program product to display, on interactive geographical maps indicating points of interest, heat areas comprising one or more polygonal areas of the interactive map having at least a threshold heat intensity indicating a quantity of points of interest and having at least a minimum number of hotels, comprising:

a non-transitory computer storage medium encoded with computer-executable program instructions that when executed by data processing apparatus cause the data processing apparatus to:

identify points of interest within a geographical region, wherein identifying points of interest within the geographic region comprises:

obtaining a plurality of geotagged photographs, wherein each of the geotagged photographs is geotagged with a location;

for each of the plurality of geotagged photographs,

classifying the geotagged photograph as a tourist photograph if a user took the geotagged photograph during a specified time interval and the user has not taken any photographs in the geographic region outside of the specified time interval; and

classifying the geotagged photograph as a local photograph if the geotagged photograph is not classified as a tourist photograph;

classifying one or more locations as tourist points of interest based on a number of tourist photographs geotagged with the locations;

display, via a client computing device, a map for the geographical region at a particular zoom level, wherein the map at the particular zoom level comprises a plurality of map tiles;

construct one or more heat areas for the displayed map using the identified points of interest, wherein constructing the one or more heat areas comprises assigning a corresponding heat intensity to each map tile of the plurality of map tiles based at least in part on a number of points of interest contained in the map tile at the particular zoom level;

determine one or more bounded areas of the map that (i) contain at least a minimum number of hotels, wherein the minimum number of hotels is at least two, and (ii) have a heat intensity indicating a number of points of interest that exceeds a threshold heat intensity;

display, via the client computing device, one or more polygons on the map, wherein each polygon encompasses at least a portion of the respective one of the one or more polygonal areas of the map that (i) contain at least the minimum number of hotels and (ii) have a heat intensity indicating a number of points of interest that exceeds the threshold heat intensity.

15. The computer program product of claim 14 , wherein a point of interest is determined using business classification data.

16. The computer program product of claim 14 , wherein the one or more polygonal areas are determined using a linear regression method.

17. The computer program product of claim 14 , wherein the one or more polygonal areas are determined using a convex hull method.

18. The computer program product of claim 14 , wherein the one or more polygonal areas are determined using a connected cell method.

19. The computer program product of claim 14 , wherein classifying each of the plurality of geotagged photographs as either a tourist photograph or a local photograph comprises:

determining that the geotagged photograph is a tourist photograph when a user took the geotagged photograph during a specified time interval and the user has not taken any photographs in the geographic region outside of the specified time interval.

20. The computer program product of claim 14 , wherein assigning a corresponding heat intensity to each map tile of the plurality of map tiles is based at least in part on a number of tourist photographs geotagged with locations in the map tile.