a strip of water covering the Grand line and said to be the nest of the Sea Kings. Calm Belt is a no place for sailing because there is no ocean and wind current plus the threat of the sea kings which makes it a great barrier for those who want to go to the grand line without passing the reverse mountain. 

Amazon Lily - the home of the Kuja Pirates where Luffy was sent by Kuma.

Rusukaina - an island near Amazon Lily where Luffy trained during the two year time skip

Impel Down - the great prison where it is impossible to break in and out except for Monkey. D. Luffy!