Hit the beach
While the New England weather makes beach culture here a purely seasonal option, Boston still has many nearby stretches of sand for seasonal—and inexpensive—day trips. Boston's North and South Shores have beautiful beaches that are less than an hour's drive from the city. For those who do not have easy access to a car, the Hub itself has several urban sandbars ideal for relaxing or taking a refreshing dip in the ocean.
However, whether within city limits or an hour's drive away, there are a number of beautiful beaches that are reasonably priced to visit. Some may charge an entrance fee or require you to pay for your T fare, but you can easily pack your own snacks and keep the rest of your spending under control. Some of the beaches recommended are Castle Island, Revere Beach, and the long list of beaches in the Greater Boston area. Hitting the beach is definitely one of the best cheap things to do in Boston.
Prices Range: $1.50 - $5 for entrance fee & T fare