I went to the Diet Library by bicycle.
The roads in Tokyo are crowded on weekdays, but not on Sunday.
I followed Aoyama Street through Shibuya.
I dropped in on the Imperial Palace. In the Edo era (1603-1868), the shogunate lived here.

The reason that I went to the Diet Library was to copy old maps. Lots of maps surveyed and published more than 100 years ago are kept here.
I can see the changes of the city and the topography "volcanic activity and river repair", when I compare current maps with old maps.