Tucked into the woods of Carroll County, Madison Boulder Natural Area protects one of the largest glacial erratics in North America — a massive boulder estimated to weigh over 5,000 tons and measuring roughly 83 feet long, 37 feet wide, and 23 feet high. Deposited by retreating glaciers during the last Ice Age, this single rock is the entire reason this 17-acre state park exists, and it’s genuinely impressive to stand beside.

A short, easy trail leads from the parking area to the boulder itself, making this an accessible stop for visitors of all ages and fitness levels. The surrounding forest of mixed hardwoods and conifers provides pleasant shade in summer and striking color in autumn. Interpretive signage explains the geological forces that carried this house-sized chunk of granite from the White Mountains and left it here thousands of years ago.

This isn’t a full-day destination — most visits last 30 minutes to an hour. But it pairs perfectly with nearby attractions in the Conway and Tamworth area, making it an easy addition to a White Mountains road trip. Birdwatching and nature photography are popular here, and the quiet forest setting offers a welcome break from busier tourist spots.

No camping facilities are available on-site, but several campgrounds operate nearby in the White Mountain National Forest. The best time to visit is late May through October, when the trail is clear and fall foliage transforms the surrounding canopy. Winter access is limited and conditions can be icy.

Explore Nearby

• Kancamagus Scenic Byway — Scenic Byway in New Hampshire
• White Mountain National Forest — National Forest in New Hampshire, Maine
• White Mountain Trail — Scenic Byway in New Hampshire
• Mount Orne Bridge — Covered Bridge in New Hampshire
• Mount Orne Bridge — Covered Bridge in Vermont