Lakeside Park was built by a group led by Denver brewer Adolph Zang, on an approximately 57-acre site located adjacent to Lake Rhoda (then known as West Berkeley Lake). Originally known as “Lakeside Park,” “The White City," and "The Coney Island of the West," the park featured the Beaux-Arts and Neoclassical architectural styles favored in many other Exposition-themed amusement parks of the era, and was lit by an estimated 100,000 electric bulbs. It was serviced by a trolley line built by the Denver Tramway, making it a trolley park; however, unlike most trolley parks, Lakeside was independently owned, and included ample space for automobile parking.

The park’s original buildings included the 150-foot Tower of Jewels at the park’s main entrance; a three-story casino building featuring a rathskellar, a theater, and dining rooms overlooking the lake; a natatorium; a 15,000 square foot ballroom; a roller skating rink; a boat house with a 160-foot pier; and a miniature train station modeled after Denver's Union Station.

The main entrance led down a wide staircase to a central park area. Rides and attractions were originally grouped at the southern end of the park, with the park's northern section reserved for social activities such as musical performances, ballroom dancing, boating, outdoor swimming and diving at the lake, and roller skating.

Original rides and attractions included the Lakeshore Railroad (a miniature railroad which circled the lake), a merry-go-round, a Ferris wheel, an airship and balloon ascension platform, a Third Degree funhouse, the Devil's Palace (described as an "interesting and instructing amusement" featuring snakes and other reptiles), a Shoot-the-Chutes, a mile-long Scenic Railway, and the Velvet Coaster. W.H. Labb of Indianapolis designed the Velvet Coaster, intended to be a combination of the Foster coaster at Chicago's White City and a type of figure-8; it featured a 1,200 foot (370 m) framework situated along the southern end of the lake, with a total of 3,600 feet (1,100 m) of track. A ride called The Tickler was installed, but was soon removed after customers received serious injuries, including broken bones.

The Derby Racer—a double-track racing coaster designed by John A. Miller—was added in 1911. The massive ride was built at the northern end of the park, which had previously been designated for social functions only, thus beginning a gradual move away from the park's White City aspirations.

The Scenic Railway and other structures in the southwestern section of the park were destroyed by a fire on November 15, 1911. Another fire in January 1912 destroyed the skating rink and damaged the Derby coaster. The coaster was repaired, while the natatorium was converted into the new roller skating rink; it would not be used for swimming again until 1928.

Following its acquisition by Ben Krasner in 1935, Lakeside underwent a period of major renovations and additions, further distancing the park from its original White City/Exhibition roots. Many new rides were added, including the Cyclone roller coaster, which replaced the Derby Racer in 1940. New buildings and features were built in the Art Deco style, including individual ticket booths for most major rides and attractions. Although most of these booths were of the standalone type, one notable exception was the Cyclone, which had a built-in ticket booth between the entrance and exit ramps. Although ride tickets (as well as unlimited ride passes) are now sold at the park’s entrances rather than at each ride, many of the original ticket booths are still in place. Architect Richard L. Crowther designed much of Lakeside's Art Deco and Modern features during this period, and included a great deal of neon lighting in his work.

There are many examples of architectural salvage to be found throughout the park. Inside the main restaurant is a marble and mirror backbar that was saved from the Denver Union Station, one of the picnic pavilions is created from a retired center column of a ride, and the pool for the Skoota Boats ride is an adaptive reuse of the original Shoot-the-Chutes ride. The main office features a functioning manual telephone switchboard that is still in use.

A fire in December 1973 destroyed the pool building, which was then being used for maintenance and off-season storage. Parts and blueprints for many of the park's rides (including the drive motors and cars for the Staride, a high-speed Ferris wheel-type ride installed circa 1916) were lost. Lakeside's ballroom, which had hosted thousands of local and national musicians and performers throughout the park's history, closed in 1972 due to declining interest in ballroom dancing. It was deemed a significant fire hazard and was largely demolished in 1974.