Eastwatch-by-the-Sea

Eastwatch, or Eastwatch-by-the-Sea, is a castle and port located at the far eastern end of the Wall, where it drops into the Shivering Sea. Eastwatch serves as the main port for the Night's Watch.

At the time of the series, Eastwatch is commanded by Cotter Pyke.

Season 1
Lord Commander Jeor Mormont tells Jon Snow that four of Cotter Pyke's men found four wights in the snow near Eastwatch. Unlike the men at Castle Black, they had the sense to burn them.

In the books
Eastwatch-by-the-Sea serves as the main resupply post for the Night's Watch, with ships stopping there from the island of Ibben, the Free Cities far to the south and even some wildling fisherfolk are permitted to trade there. There is also some clandestine smuggling going on there, which is tolerated only as far as in that it helps the Watch.