Seaside Adventure in the City: Castle Island, Pleasure Bay, M Street Beach & Carson Beach in South Boston, Massachusetts
Looking for a beach day without leaving the city? Just minutes from downtown Boston, Castle Island, Pleasure Bay, M Street Beach, and Carson Beach form a scenic stretch of connected waterfront parks in South Boston, Massachusetts. These four destinations offer an unbeatable mix of history, recreation, and classic beachside fun — all with sweeping views of Boston Harbor. From kayaking around the bay to exploring historic Fort Independence or playing beach volleyball with friends, this cluster of coastal gems is where locals head when the weather is right and the water calls.
Top Things to Do at Castle Island and Pleasure Bay
Explore Fort Independence and Seaside Trails
The centerpiece of Castle Island is the star-shaped Fort Independence, one of the oldest coastal fortifications in the U.S. While guided tours are seasonal, the grounds are always open for exploration.
- Stroll the Harborwalk that loops around Castle Island and Pleasure Bay
- Snap photos of planes taking off from nearby Logan Airport
- Learn local history through interpretive signs around the fort
Family Fun and Waterfront Views
This area is tailor-made for families, with plenty of flat paths, green space, and kid-friendly attractions.
- Playground near the parking area for younger children
- Picnic areas with shaded tables and harbor breezes
- Sullivan’s snack shack serving up fried clams, hot dogs, and ice cream since 1951
Water Activities at Pleasure Bay
Pleasure Bay features calm, enclosed waters perfect for water sports and a relaxing swim.
- Kayaking and paddleboarding on flat, protected water
- Windsurfing for more adventurous paddlers
- Fishing along the causeway and seawall
Relax and Recreate at M Street Beach and Carson Beach
City Beaches with a Local Vibe
Just a short walk from Castle Island, M Street Beach and Carson Beach offer wide sandy shores and a welcoming, neighborhood feel. They’re local favorites for both laid-back lounging and active play.
- Soft sand for sunbathing and easy water access for swimming
- Beach volleyball courts at Carson Beach (bring your own ball!)
- Walking and biking paths connecting all three beaches
Visitor Amenities and Accessibility
Each beach is equipped with helpful services and infrastructure to make your visit smooth and comfortable.
- Restrooms and changing facilities at Castle Island and Carson Beach
- Multiple parking areas, plus easy access by public transit
- Lifeguards on duty at designated swim areas in summer
What Makes This Waterfront Stretch Unique?
What sets Castle Island and its neighboring beaches apart is the rare combination of urban access and coastal immersion. You can ride the Red Line, hop off in South Boston, and be on the sand in minutes. The interconnected layout of the Harborwalk trail allows you to enjoy a full day of movement — walking, biking, or skating — with scenic harbor views and convenient amenities the entire way. Add to that a dose of Revolutionary War history, a buzzing local food scene, and plenty of space to spread out, and you’ve got one of the most dynamic and family-friendly parks in the state.
Visitor Tips
- Arrive early on weekends — parking fills quickly, especially at Castle Island
- Bring a kite: Windy afternoons near Fort Independence are ideal for flying
- Pack layers: The breeze off the harbor can be strong, even on hot days
- Public transit: Take the Red Line to Andrew Station and walk or bike to the beaches
- Don’t miss Sullivan’s: Their lobster roll and shakes are iconic
Local Tip: Sunset Strolls with City Views
While daytime is great for swimming and lounging, locals know that sunset at Castle Island is something special. Head to the end of the causeway as the sun dips behind the Boston skyline and casts golden light across the harbor. It’s one of the city’s best low-key spots to unwind after a summer day — and it’s free.
From beach volleyball and harbor kayaking to fried seafood and historic walks, Castle Island and the connected South Boston beaches are where city meets sea in the best possible way. Whether you’re a first-time visitor or a born-and-raised Bostonian, these coastal parks offer the perfect escape just minutes from the city grind.