Any trip around Japan will not be complete without finding it’s manhole cover, so while walking around the city I finally found it near the the peace park.
The design depicts the city’s flower, Ajisai (Hydrangea).
Unfortunately, this time I could not find the colored version.
Maybe you will luckier than me when you visit Nagasaki.
Maniniyot 
Dear Friend!
Greetings!
Very interesting manhole cover! Could you be kind to send a copy to me!
Big thanks in advance!
Best regards,
Robert-Gilles