There is a white sand beach where you are welcome to bring your dog just South of Boston in the town of Plymouth. Yes, the same town made famous by the pilgrims around 1620. Plymouth has much more to offer in addition to a beautiful white sand beach, making the hour trip from Boston worthwhile. You will need to keep your dog on a leash while you are here but you can easily go swimming with your dog when the beach gets too hot.
If you head south along the water from the town center, you will find the entrance to Long Beach on your left. Non-residents pay $15 to park in the first lot. Residents with four wheel drive vehicle can drive up to the next day lot. But everyone is welcome to walk with their dogs. You should note before going that dogs are not allowed past the second parking lot due to nesting shore birds.
Unlike the Cape Cod National Seashore, dogs can be in the lifeguarded areas. In fact most of the beach along the first lot where we parked our car had lifeguards. The parking lot is just over the seawall making the process of setting up camp on the beach for the day an easy process. The sand is clean and white, the water clean and cool; this is a beautiful beach that is easy to get to.
After your day in the sand, you should take some time to explore Plymouth. The town is great and the harbor is beautiful. You can easily spend some time exploring the shops and restaurants. You might even consider getting take-out and having a picnic near Plymouth Rock. The grassy areas and parks are perfect for a late evening dinner under the trees in this historically important New England town.