William Sewall House, Greek Revival residence in Island Falls, US

The William Sewall House is a residential building in Greek Revival style located on Crystal Road in Island Falls. The structure has two and one-half wooden stories with twin interior chimneys and clapboard siding throughout.

Levi Sewall settled in Island Falls in 1842, and his tenth child, William Wingate Sewall, born in 1845, was the town's first native-born resident. Neighbor Osgood Pingree built this house for William in 1865. Theodore Roosevelt first visited in 1872, stayed three times, and last came in 1878; the friendship lasted until Roosevelt's death in 1919.

The house was a well-known stop for hunters working and recreating in the Maine woods. Since 1997 it has run as a yoga retreat, with vegetarian and vegan meals and retreats for women, writers and artists. USA Today ranked it second among US yoga retreats in 2023; it opens May through October.

The house operates as a yoga retreat center from May through October, run by instructor Donna Amrita Davidge, a great-granddaughter of William Sewall. It sits on the north side of Crystal Road (Route 159), just west of the Island Falls Post Office. The retreat serves vegetarian and vegan meals and hosts sessions for groups such as women, writers and artists.

Since 1997 the house has run as a yoga retreat under Donna Amrita Davidge, a great-granddaughter of William Sewall; the retreat is vegetarian and vegan and runs from May through October. In 2023 USA Today ranked it second among the ten best yoga retreats in the United States.