The Tassajara Zen Center is a monastery and retreat center. It is one of the three practice centres that make up the San Fransisco Zen Center. The center is ocated in the Ventana Wilderness area of the Los Padres National Forest, southeast of Carmel-by-the-Sea, California, is the oldest Japanese Buddhist Sōtō Zen monastery in the United States. It is not easily accessible and only open to visitors during the summer. The rest of the year students practice for 90 day periods.

The 126-acre mountain property surrounding the Tassajara Hot Springs was purchased by the San Francisco Zen Center in 1967 from Robert and Anna Beck. When it was purchased it was the first Zen monastery outside Asia. The name is a corruption of Tasajera, a Spanish-American word derived from an indigenous Esselen word, which means ‘place where meat is hung to dry. The Center is very isolated, more than 16 miles (26 km) from the nearest paved road, and only accessible via a narrow, steep, one-lane dirt road. During the winter months, practitioners live alone on site. During the summer months (tourist season), the Center is opened to day and overnight guests. The hot springs on the property have been developed into Japanese-style baths.

There are several programs that enable interested students to live and work at Tassajara. There are two ninety-day practice periods (one in Winter and one in Fall) that follow the traditional Soto Zen monastic schedule and allow experienced practitioners to join with the Tassajara community in intensive practice at Tassajara Zen Mountain Center (Zenshinji–Zen Heart-Mind Temple). From late September until early April, 50 - 60 students rise before dawn and begin a full day of zazen (seated meditation), study, and work, following a traditional Buddhist monastic schedule When Guest Season commences in May, the monastery opens its doors to the wider community. The focus turns from the primarily inward activity of “practice period” to serving the wider community and sharing the experience of Zen practice and the joys of Tassajara. Since Zen Mountain Center’s inception, the Guest Season has been an integral part of the yearly cycle in these mountains.