Shag Rocks are barren rocks situated 8 nautical miles offshore of Custom House Tower

Custom House Tower

The Custom House Tower - now Marriott's Custom House Hotel - is a skyscraper in McKinley Square, in the Financial District neighborhood of Boston, Massachusetts, in the United States. Construction began in the mid-19th century; the tower was added in the 1910s...

 in downtown Boston, in the Boston Harbor Islands National Recreation Area

Boston Harbor Islands National Recreation Area

The Boston Harbor Islands National Recreation Area is a National Recreation Area situated among the islands of Boston Harbor of Boston, Massachusetts. The area is made up of a collection of islands, together with a former island and a peninsula, many of which are open for public recreation and some...

 and within the city limits of Boston. The rocks are northeast of Little Brewster Island

Little Brewster Island

Little Brewster Island is a rocky outer island in the Boston Harbor Islands National Recreation Area. It is best known as the location of Boston Light, the only remaining Coast Guard-manned lighthouse in the United States, and an important navigation aid for traffic to and from the Port of Boston...

 and east of Great Brewster Island

Great Brewster Island

Great Brewster Island is a one of the outer islands in the Boston Harbor Islands National Recreation Area, situated some offshore of downtown Boston. The island has a permanent size of , plus an intertidal zone of a further...

 and have been the site of several shipwrecks. Boston Light

Boston Light

Boston Light is a lighthouse located on Little Brewster Island in outer Boston Harbor, Massachusetts. The first lighthouse to be built on the site dates back to 1716, and was the first lighthouse to be built in what is now the United States...

on Little Brewster Island warns mariners to steer clear of the rocks. Public access is impractical.