While some parks are quite visible from a distance, the first glimpse of many theme parks has been a roadside sign welcoming guests to the property.

Great Adventure's original Lion Sign was the first thing guests saw as they approached the entrance road on Route 537.  With Great Adventure's acquisition by Six Flags in 1977, a decision was made to update the roadway sign for the 1978 season with the park's new full name and logo, as well as a marquis to announce special events in the park.
The rainbow sign was designed with two steel support columns with golden spheres on top framing an arched rainbow-shaped light box and marquis. The base of the sign was a planter made of the same stone used in many locations throughout the theme park which was filled with small shrubs and seasonal flowers.
The sign marquis was used to advertise all kinds of events happening at the park through the years. Corporate picnics, concerts, the opening of new attractions, park hours and schedules, were all posted at different times of the season displayed on the two-line changeable letter marquis.

The sign became an icon of Six Flags Great Adventure creating the first impression of the park as guests arrived and prompting carloads of kids to scream in delight. With the park hidden from view by the heavily wooded property it really was the only indication of the Great Adventure's existence from the road.

The florescent tube lit plastic sign marked the park's entrance for fifteen seasons before being removed and discarded.  The removal not only included the actual sign but the stone planter and landscaping as well.
For the 1992 season, the Rainbow Sign was replaced with the more generic Six Flags logo sign which included six flag poles and a fountain base. This was part of the company's branding strategy as they aggressively improved and marketed their parks nationwide rather than just locally.

For the 2022 season, the blue banner logo was replaced with a new, more colorful sign which featured the updated corporate logo and an electronic color video marquis to create a new first impression of the park.
Two signs within the theme park had similar features of the highway sign.  The signage for Lightnin' Loops originally had a smaller version of the rainbow light-box, and a near duplicate sized marquis was also added to the Great Arena entrance.  All three were added at approximately the same time by the Six Flags management team.
Original Spotlight:  November 9, 2022.  GAH Reference#:  SIGN-1978-001