When Oregon was officially made a state 150 years ago, Seaside was already on its way to becoming the Northwest's first beach resort town. Visitors would travel down the Columbia River to Astoria, then ride a stagecoach to Seaside. By the 1870s, Seaside was the Northwest's premier coastal destination when Ben Holladay's Seaside House resort attracted prosperous clientele to the wild Oregon coast.

In the late 1880s, a rail line was finished and the stagecoach trip was replaced with a short train ride. A crude shell-paved road led from the railroad stop to the beach and as the destination's popularity grew, so did businesses along that shell-paved road. You can walk that road today with a stroll down Broadway, Seaside's main street that ends at the Pacific. Toward the east end of Broadway, at Holladay Drive, are some of the city's oldest buildings. The Gilbert Building was completed in 1915 and this historic district is now filled with shops, galleries and restaurants. Where Broadway ended at the beach, a wooden boardwalk ran parallel to the shoreline. In 1920, the promenade was paved with concrete and a unique roundabout was constructed at the end of Broadway. Today, these famous landmarks are known simply as the Prom and Turnaround and, along with Broadway, are the center of activity in this beach town. In 1937, the Seaside Aquarium opened on the Prom in a building dating from 1914 that had once housed an indoor saltwater swimming pool. Today, people walk, jog and bike along the 1.5-mile Prom and enjoy the broad views from the Turnaround. Visitors can still feed the seals at the aquarium as they have done for over 70 years. A statue of Lewis and Clark now sits in the center of the Turnaround commemorating the visit from the famous expedition in 1806.