Walk four kilometres of actual gas flame
149 lamps, all burning real gas
A dusk walk along about 4 km of streetlamps in the Bashamichi and Kannai district: 60 on Bashamichi-dori, 18 on Bankokubashi-dori, 31 on Kaigan-dori and 40 on Yamashita Park-dori. A monument and a period replica stand outside Kannai Hall.
Why it's unique
Japan's first public gas street lighting was lit in Yokohama on 31 October 1872, and the date is now marked nationally as Gas Memorial Day. The claim is specifically street lighting: the first gas flame in Japan was at Satsuma's Isogahama in 1857.
What makes it something to do rather than a plaque is that the lamps are still gas. All 149 along the route burn real flame, lit by an electric timer at dusk rather than by a lamplighter, so you can walk the whole of it after dark.
Before you go
Go after sunset, or there is nothing to see.
Four of the 149 lamps are genuine British imports replicating the Trafalgar Square, Houses of Parliament, Victoria Tower and Sheffield Park designs, so look for the odd ones out. The paving tiles along the district carry an embossed gas-lamp motif, which means you can follow the route by looking down.