Located directly behind the bridge, the observation lounge was the main conference room for the bridge crew to discuss upcoming missions or carry on any sort of work meeting. Due to the ship's status as Federation flagship, it was also the place of diplomatic meetings with high ranking officials from other polities being hosted on board the ship.
The port side door leads down into deck two, while the starboard side door leads back to the main bridge. The front wall has a decorative display of previous ships named Enterprise.
(The real life set had somewhat different looking sculptures, as the ones depicting the Enterprises B and C were different to how those ships were eventually portrayed. For this reproduction, I decided to "correct" this, as a personal prerogative, and showcase both of those ships with their "real" in-universe shapes.)