The flexed arm of 15 Massachusetts towns sticking out into the Atlantic is a unique part of New England. You sense something’s different as soon as you cross over the Bourne or Sagamore bridges high above the Cape Cod Canal.

Here are some considerations.

1. It has four different sections, and they can be confusing. The Upper Cape is what you encounter immediately over the bridge, while the Lower Cape, or Outer Cape, is what comprises the wrist and hand of the upraised arm. Got it? That always feels reversed to me. And in-between are the Mid-Cape and Lower Outer Cape. Usually added to that are “the islands,” Nantucket and Martha’s Vineyard, which you reach by ferry.
2. The Cape is infused with a Colonial appearance, despite all the development since, or at least since the high Victorian era. And it’s definitely integrated with the ocean, on both sides. It often becomes overwhelmingly twee, though the thrift shops can be well worth investigating. Make sure your American flag has only 13 stars.
3. What people usually think of as the Cape is its far outer tip – the glorious sand dunes and then flamboyant Provincetown. For me, the heart of it all has been the Portuguese Bakery in P’town. Cheap, blue collar, and distinctively tasty, until recently. Portuguese, after all, have long been the fishermen.
4. The Cape is noted for its lighthouses – 18 still working, last I counted. Some of them are privately owned.
5. Chatham, at the elbow, has a gazillion big seals – and a shark population that feeds on them. You can get close-up views of the seals at the town’s commercial fish dock.
6. The sandy cliffs and beaches along the Atlantic run for miles, from Marconi station on up to P’town. You can just walk and walk and walk, maybe returning on the converted railroad trail up above.
7. Traffic jams are a constant headache through summer, especially on weekends.
8. The Cape pushes the ocean current further out to sea, meaning colder waters rise up in the void to its north. For swimmers, that means warmer waters on the Cape than we have in New Hampshire or Maine, beginning earlier and later into the season, too. By the way, the Plymouth Bay side is usually warmer and gentler.
9. Bicycling is big.
10. I suggest going in the shoulder season, before Memorial Day and after Labor Day. Good swimming can extend through September, if hurricanes cooperate. For the rest of the year, the weather can be weird. Remember, the Cape’s at the mercy of the ocean.