Many people know me as a food writer, mainly for posting reviews of little-known dining spots and writing news stories that focus on the Boston-area restaurant scene. But I’m also a hike leader, having led walks and hikes for the Appalachian Mountain Club for about 15 years now, and as I lead about 25 outings a year all over the local region, it often feels of late that I pretty much know every area in which to hike. Well, that thought went right out the window recently after an acquaintance in the restaurant business asked me if I had ever hiked to Thompson Island. I told him no because I haven’t yet learned how to walk on water, but he said there is a much easier (and much less scary) way to get out there, and that’s when I learned about one of the city’s best outdoor secrets.

Thompson Island is a relatively small area of land that’s closer to the mainland than most islands in Boston Harbor, and it is one of two islands that you can actually walk to at low tide via a sandbar. (And sorry, but I can’t tell you the other because it entails cutting through private land—a big no-no.) And what makes this so little known is the fact that the sandbar is almost completely hidden from view from any roads, so unless you’ve been told about it, you probably won’t even know that it’s there. Getting to the sandbar is actually quite easy—turning east on East Squantum Road in Quincy from Quincy Shore Drive (by Wollaston Beach) will quickly get you into the quiet Squantum neighborhood where the road becomes Dorchester Street, then Moon Island Road before you hit the end of the line at a guard gate, where the road—which at this point becomes no access—continues on to Moon Island. Free parking is available along the right side of the road just before the guard gate or in a small dirt lot on the left a few hundred feet back, though make sure you heed the signs if you park on the road, because on weekdays, there is a two-hour limit for much of the day.

A recent trip I led to Thompson Island turned out to be about as easy a walk as I’ve done for the AMC, as there are very few steeps and not much in the way of distance, making it a trip that even beginner hikers can do. The start of it is actually the toughest part, as the dirt trail from either the parking lot or to the left/behind the American Legion (which is across from the street parking area) is curving and narrow and at times has steep dropoffs to the right. It is also a bit tricky at the start because the small park behind the Legion hall contains a number of short trails, so it is easy to get off course; the key is to make sure the water is always on your right once beyond the Legion building. About 5-10 minutes into the hike, the trail basically ends at a drop down to the water on the left and a ledgy cliff that leads up to the right. For our hike, before dropping to the shoreline we scrambled up the cliff to see where we were about to go, and the views from the cliff were among the best in the entire Boston area, showing the crescent-shaped sandbar winding its way out to sea and connecting on the other side to Thompson Island in the distance.

We reached the start of the sandbar approximately an hour before high tide, and it was already dry and surprisingly wide—much wider than I had thought it would be, as I assumed it might have room for maybe one or two across, but it appeared to be at least 50-100 feet wide and was getting wider by the minute. Still, the rule of thumb is try not to head onto the sandbar more than 90 minutes before low tide and definitely do not return from Thompson Island more than 90 minutes after low tide, possibly making sure you are close to the sandbar an hour after low tide to make sure the sandbar isn’t disappearing too quickly. Why is this? I’ve been told that at mid-tide, the water where the sandbar is can be waist-high.

Walking across the sandbar was such an unforgettable experience for our group that it was almost good enough to do alone without even going to the island (and keep this in mind, as you’ll soon learn that the island itself has some restrictions). To the right we saw little Moon Island, the much-larger Long Island, and the space where the bridge connecting the two had been; to the left were jaw-dropping views of the Boston skyline, UMass Boston and the Kennedy Library, and much more. And while the sandbar was wide and flat, the footing wasn’t always perfect, with pebbles, sand, seaweed, and occasional streams of water causing us to slow the pace a bit. About 15-20 minutes after leaving the Squantum shoreline, we reached Thompson Island—and were greeted by a rather menacing “No Trespassing” sign. From this spot, you have options depending on when you go: If it is a weekday, we’ve been told that you’re allowed to walk along the waterline (basically the beach area below the high-tide mark), and fortunately the beach area stretches nearly all the way around the entire 200-acre island, complete with tremendous views of the island and open ocean along the east side (which is the most obvious direction to go from the sandbar) and more Boston skyline views and potential sunset scenes along the west side; if you go on a weekend, the entire island—minus the campus area where youth and education programs take place—is open to the public, which means you can walk along a handful of trails and dirt roads within the island itself, including a wide tree-shaded one that winds its way down the backbone of the island south of the campus and leads to the west side of the sandbar, with views of marshes and fields along the way.

So what are the best options for hiking to Thompson Island? A weeknight around sunset (which is what we recently did) is a fine choice, as long as you make sure you stick to the waterline on the island and get to back to the sandbar before sunset, because the short trail from the sandbar to the road can get very dark. But perhaps the best option is to go on a weekend, time it so you get to the sandbar 90 minutes before low tide, and enjoy a couple of hours of wandering around the island before heading back about an hour after low tide. No matter when you go, however, be ready for some views that will blow your mind and some bragging rights when you tell your friends that you walked across Boston Harbor and didn’t even get your feet wet.

SQUANTUM TO THOMPSON ISLAND HIKE. 4-6 MILES TOTAL, 2-3 HOURS. PARK ALONG MOON ISLAND RODE BY AMERICAN LEGION POST AND MOON ISLAND GUARD GATE AT GPS COORDINATES 42.3027669,-71.0111489. MAP OF THOMPSON ISLAND AT THOMPSONISLAND.ORG

9/19/16 UPDATE:

After our original story ran, Outward Bound and the National Park Service informed us that the information DigBoston was originally given was in fact incorrect. According to both parties, there was a miscommunication and in fact the public is not actually allowed to find their way to Thompson Island including via the sandbar from Squantum in Quincy during low tide. Outward Bound says that the only way for the public to access the island is by ferry, which runs on weekends, from Memorial Day to Labor Day. In addition, Outward Bound has informed us that the water’s edge/beach area on the island is not open to the public, although questions remain since it is our understanding that the lands below the mean high water mark out to the ocean is always accessible to the public in the state of Massachusetts.

In short, the island itself is not open to the public from Labor Day to Memorial Day as we originally reported, and is only accessible by ferry on weekends between Memorial Day and Labor Day. As to the question of whether or not walking along the water’s edge on Thompson Island is legal, we are looking into this further and will update this article once we have more information. However, the sandbar is not part of the island so that should be ok, as there are no signs to indicate otherwise, so people can walk from Squantum to Thompson Island but have to turn around when they reach the island itself.