McGregor Park, also known as Hippie Hollow, is a park located on the shore of Lake Travis near Austin, Texas. Though the land is owned by the Lower Colorado River Authority, it is leased to Travis County, Texas, whose Parks Department administers the park.

Hippie Hollow got its name due to its traditional use as a nude swimming, or "skinny-dipping", spot beginning in the early 1960s. This usage continues to this day, though that status has been unsuccessfully challenged in the courts. The clothing-optional status is protected by the placement of appropriate signage at the park entrance, which duly warns visitors of possibility of encountering nude swimmers.

While some may refer to Hippie Hollow as a nude beach, that description is somewhat misleading; the lake shore is a somewhat steep slope which consists of limestone steps that can be quite rugged in some spots. While some observers might find that feature to be somewhat incompatible with the lack of clothing, park users have adapted quite well, preferring it to the sandy beach and salty waters that are characteristic of most nude beaches.