Unreleased neighborhoods

There have been several neighborhoods made by Maxis and Electronic Arts for The Sims 2 and The Sims 3 that were never released to the public. Riverside and Waterside were used in previews for the pre-released The Sims 2 but never released, and a third neighborhood named Sedona is referenced in game files. Two versions of Sunset Valley were made but due to the delay of the release of The Sims 3, additional changes were made.

Riverside
250px|thumb|Riverside flyby. Riverside was originally set to come with The Sims 2 base game, but many changes caused it to be removed. Although there were no specific families that were scheduled to come with it, there is a high speculation that families in the various previews may been the inhabitants of Riverside. Oddly the neighborhood description for Riverside remains in the neighborhood manager files, though unlike Waterside the text is missing. A recreation of Riverside has been attempted by Thsms204. It can also be seen that the template for custom Pleasantview and riverside are the same, hinting that Riverside was renamed Pleasantview, and had most of the lots and families removed. The Riverside recreation project has ended at February 2010.

Waterside
Waterside was a neighborhood used for previews of The Sims 2. It was founded by Tim LeTourneau. It was originally set to come with The Sims 2 base game, but many changes caused it to be removed. It is the assumed home of various Sims including Dina (similar to Dina Caliente), Laura, and Tina (all past girlfriends of Don Baxter). It is known to be the home of the Baxters, Virginia, and many other relatives to the Baxters. Oddly the neighborhood description for Waterside remains in the neighborhood manager files. Waterside also has some lots that can be found in the lots and houses bin, as you can clearly see the cape cod classic in the lower right hand corner in the picture above. A recreation of Waterside has been attempted by GPKman.

Sedona
A neighborhood named Sedona is referenced in neighborhood manager, however the file is text-less and it was not featured in any previews for The Sims 2 so details are scarce. It is likely associated with the neighborhood template Sedona.

It can also be speculated that these were the intended to be released neighborhoods, where as Riverside and Waterside would be Pleasantview and Veronaville, and Sedona would be Strangetown. A recreation of Sedona is being attempted by ParanormalJ.

Unused flythroughs
Hidden within the game are a number of neighborhood camera flythroughs that are not used, but are still associated to specific neighborhood names. It is possible to enable these for use for any neighbourhood by simply renaming it to one of the following:
 * Sedona
 * Europa
 * Lakeview

As the flythroughs follow pre-determined coordinates, a neighbourhood's terrain may not be ideal for them. The camera might clip through terrain and lots.

Sedona still exists, you can create it as custom neighborhood.

The Sims 3
Even though Sunset Valley was shipped with the game, two versions were made but never released. The first version was made in March 2008 but was revamped. Then the second was made after that and was supposed to release in February 2009 but was delayed. Because of this, EA decide to change the neighborhood up a bit.