You can remove tourists and other detritus from your travel photos using either ImageMagick or the Gimp. Put your camera/phone on a tripod and then take a number of photos waiting between each photo so that any people in the way have moved. You will need enough shots for every part of the scene to be unobstructed.
To use ImageMagick, put all the photos into a directory and run the command line:
convert *.jpg -evaluate-sequence median output.jpg