The NH Seacoast is the vicinity of Hampton and Portsmouth, NH. The edges blur between towns, so locals usually just call it "the Seacoast." And so, when I carved my first Seacoast-related letterbox stamps, I didn't realize that others had used that same name for their stamps/boxes, too.

However, a stamp is a stamp, so--when I planted them--some of mine bore the name "Seacoast."

Seacoast¹ Letterbox - Rediscovered

This first letterbox was actually on the trail to an earlier (and, frankly, far better) drewclan letterbox. It was at Odiorne Point Science Center park. And, in case you're trying to figure it out, the stamp is supposed to show a lighthouse.

Odiorne Point Science Center park is an ideal spot for hiking, birdwatching, or letterboxing.

Update 7/06 - Since this letterbox was reported as found, I'm restoring the original clues:

Follow the clues as if you're going to Seacoast/Rye letterbox.

From that page:

"On NH Rte. 1A just outside Portsmouth. Park at the main state park entrance by the Science Center.

"Between the parking lot and the Science Center, climb the stairs over the Battery and follow the trail northwards down, across the road, and into the woods. The trail follows beautifully northwest along the coastline. Stick with the wide main path when it curves left a little, away from shore. At an amazing row of sugar maples, fork right to a large bunker."

When you reach the large bunker (looks like a huge concrete bridge, with graffiti, of course), pause so you are facing the opening to the bunker. On your left and right, the path through the bunker is marked with large boulders.

Head towards the second boulder on the left, starting from the path you were on. It's not the most comfortable seat in the world, but sit on it anyway. Have your back to the path.

Reach down to check your shoelaces, and move the smaller rock away from the one you're sitting on, so the crevice under the bigger boulder is revealed. The treasure is in there, underneath the rock you're sitting on.

This is a popular spot, so be discreet as you remove and stamp the letterbox. However, even on a busy day, there are usually enough breaks in the hiking traffic that you can unobtrusively stamp and replace the box.

Be sure to replace that smaller rock so the box is fully hidden from view. Thanks!

Then, please continue following the clues to the drewclan letterbox, because it's a lovely stamp and the view from its hiding spot is spectacular!

Seacoast² Letterbox - Missing

This stamp--now missing--was at the Urban Forestry Center, not far from Yoken's in Portsmouth, NH. It's an ideal location for letterboxing, but the mosquitos can be ferocious during a warm, damp year.