Castle Island is a 22-acre waterfront park in South Boston, home to the 19th-century granite Fort Independence. It is managed by the Massachusetts Department of Conservation and Recreation. This guide covers opening hours, ticket prices, transport and parking, accessibility, and practical visitor tips.
This guide was updated in July 2026. Free guided tours of Fort Independence are running for the summer, Saturdays and Sundays from noon to 3pm, with Thursday twilight skyline viewings from 7pm to dusk in June and July. All Fort openings depend on weather and are occasionally affected by special events
Quick facts
| Opening hours | Park: dawn to dusk, daily, free. Fort tours: Sat–Sun, noon–3pm (summer) |
| Ticket prices | Free; the park and Fort tours have no admission fee |
| Address | 2010 William J Day Boulevard, South Boston, MA 02127 |
| Nearest transport/parking | MBTA Bus 9 from Andrew Station; free on-site parking |
| Typical time needed | 1–2 hours |
Castle Island opening hours
Castle Island is open daily, dawn to dusk, with no admission fee.
Free guided tours of Fort Independence, run by volunteers from the Castle Island Association, take place on Saturdays and Sundays, noon to 3pm, from Memorial Day weekend through Labor Day; after Labor Day, tours run on Sundays only. Thursday Twilight Skyline Viewings, from 7pm to dusk, run through June and July. All tours are weather-dependent and can be cancelled at short notice.
5 great Boston experiences to book
- ⚾ See why Boston has America’s most beloved baseball ground on a Fenway Park tour.
- 🚶 Get a history crash course on a small group walking tour along the Freedom Trail.
- 🌅 See the skyline from the water on a sunset harbour cruise.
- 🎓 Hear the stories behind America’s oldest university on a campus walking tour of Harvard University.
- 🍩 Indulge in Boston’s best donuts on a sweet treats walking tour.
Castle Island ticket prices
There is no fee to enter Castle Island or to take a guided tour of Fort Independence, which is run entirely by volunteers in cooperation with the state.
Groups wanting a private or special tour can arrange one in advance by emailing the Castle Island Association.
Opening hours and tour schedules were checked on the official Castle Island page and the Castle Island Association’s site, and last updated in July 2026.
Why book the Go City Boston Pass?
- 🏛️ 45+ Top Attractions: Enjoy admission to Boston’s most iconic sites, including the Museum of Science, New England Aquarium, and the View Boston observation deck.
- 🚌 CityView Trolley Tour: Get your bearings and travel between major landmarks with an included hop-on hop-off trolley ticket that covers the city’s historic districts.
- 👣 Freedom Trail & History: Step back into the American Revolution with guided walking tours of the Freedom Trail and entry to the Paul Revere House and Old State House.
- 💰 Exceptional Value: Save up to 50% compared to purchasing individual gate tickets, making it the most cost-effective way to see the city’s premier highlights.
- 📱 Total Digital Convenience: Simply scan your pass from your smartphone for entry and use the included digital guidebook to plan your custom itinerary on the go.
How to get to Castle Island
Castle Island is at the end of William J Day Boulevard in South Boston, reached by both a pedestrian and vehicular causeway.
By car from downtown Boston, take I-93 South to exit 15 for South Boston/Seaport Boulevard, merge onto the South Boston Bypass Road, and follow it until it becomes William J Day Boulevard; continue about 2 miles to the end of the road. By public transport, take the MBTA Red Line to Andrew Station, then the number 9 bus toward City Point, getting off on William J Day Boulevard for a short walk to the park.
Parking at Castle Island
Free parking is available in the on-site lot, with additional street parking along William J Day Boulevard. The lot can fill on summer weekends, so arriving earlier in the day helps.
How long to spend at Castle Island
Most visitors spend one to two hours at Castle Island, walking the Castle Island Loop or the longer Pleasure Bay Loop and taking in the harbor views.
Visitors joining a guided Fort Independence tour, which typically lasts 35 to 45 minutes, or stopping for food at the seasonal Sullivan’s snack shack, should allow extra time.
Accessibility at Castle Island
Fort Independence is wheelchair accessible only on its first level; upper bastions and stairways aren’t accessible.
The park’s paved paths, including the Castle Island Loop and Pleasure Bay Loop, are flat and suit wheelchair users and visitors with limited mobility.
Inside Castle Island: what to see
Fort Independence, a pentagonal, five-bastioned granite fort built between 1834 and 1851, is the eighth fortification on this site since the 1630s, making it one of the longest continuously fortified locations in the country.
The Castle Island Loop (0.79 miles) and Pleasure Bay Loop (1.84 miles) are both flat, paved walking paths with harbor views, popular with runners and dog walkers.
A 15-inch Rodman Gun, visible from Bastion A, gives a sense of the fort’s coastal defence role through the Civil War and both World Wars.
According to local legend, the writer Edgar Allan Poe served at the fort in 1827 under an assumed name, and a story he heard there is said to have inspired his short story “The Cask of Amontillado.”
Sullivan’s, a seasonal snack shack near the fort, is a Castle Island institution, though it doesn’t take reservations and can draw long lines on busy days.
Practical visitor tips
| Topic | Tip |
|---|---|
| Timing | Visit on a weekday morning for a quieter walk, especially in July and August. |
| Crowds | Weekend afternoons in summer are the busiest, with the parking lot often full by mid-morning. |
| Layout | Start at the fort before continuing around the Castle Island or Pleasure Bay loop. |
| Entry process | No tickets or check-in are needed for the park or the free Fort tours. |
| On-site logistics | Bring cash or a card for Sullivan’s, and expect a queue on warm weekends. |
Frequently asked questions about Castle Island
| Question | Answer |
|---|---|
| Is Castle Island free to visit? | Yes, the park and the guided Fort Independence tours are both free. |
| Do you need to book a Fort tour in advance? | No, tours are first-come, first-served; only large groups need to arrange ahead. |
| Is Castle Island open on Sundays? | Yes, the park is open daily, and Fort tours run on Sundays too. |
| Is Castle Island wheelchair accessible? | The park’s loop paths are accessible, but only the fort’s first level is. |
| Is Castle Island still an actual island? | No, it’s been connected to the mainland by a causeway since 1928. |
Things to do near Castle Island
Carson Beach and M Street Beach, part of the same DCR waterfront park system, are a short walk away.
The John F. Kennedy Presidential Library and Museum, overlooking the harbor, is about 10 minutes away.
Marine Park and Joe Moakley Park, green space adjoining the shoreline, are a short walk away.
The Seaport District, with restaurants and the Institute of Contemporary Art, is about 10 minutes away.
The Boston Harbor Islands, reachable by ferry from downtown, are about 20 minutes away.
What to visit tomorrow
Georges Island and Fort Warren, a Civil War-era fort in the Boston Harbor Islands, is about 45 minutes away, including the ferry crossing.
Fort Revere Park in Hull, with coastal fortifications and a water tower, is about 30 minutes away.
Fort Sewall in Marblehead, a small harbor-front fort with scenic views, is about 45 minutes away.
Fort Adams State Park in Newport, Rhode Island, one of the largest coastal forts in the US, is about 1 hour 15 minutes away.
Fort Phoenix State Reservation in Fairhaven, a Revolutionary War-era fort, is about 1 hour 15 minutes away.
More Boston travel
Other Boston travel guides on Planet Whitley include:
- Tackle the key sites on the Freedom Trail: The Old South Meeting House, the Old State House, Paul Revere House and the Old North Church.
- Use the Boston CityPass to visit the New England Aquarium, Museum of Science, Franklin Park Zoo and View Boston observation deck.
- Go back in time at the Boston Tea Party Ships and Museum.
- What you need to know about the Isabella Stewart Gardner Museum in Boston.
- Exploring the Frederick Law Olmsted National Historic Site, JFK Birthplace and Olmsted Park in Brookline.
