Click on the worlds that are bold-faced to go to their page, which includes history, lots and households, and pictures. Unless noted, this pertains to Shelli’s Worlds (rather than the specific alternate universe during The Sims 2 timeline).
SimNation
A large continent of varying weather and topographical features, SimNation includes these worlds from Northeast to West:
Granite Falls
Brindleton Bay
Willow Creek
Magnolia Promenade
Newcrest
Britechester
Evergreen Harbor
San Myshuno
Del Sol Valley
Oasis Springs
StrangerVille
The Old Country
Made famous by Princess Cordelia, the continent known as The Old Country is about half the size of SimNation.

Windenburg, the largest inhabited world lies in the southern portion of the Old Country. With its rich history, mountains, rolling hills, rivers, and sea influencing the world today, Windenburg blends its storied past with its vision of the future.

The rural village of Henford-on-Bagley is a large island off the northwestern coast. Tucked in the middle of the continent are the towns of Forgotten Hollow and Glimmerbrook.
Mt. Komorebi
Mt. Komorebi is located west of SimNation and is surrounded on all sides by water.
Sulani

The residents of Sulani appreciate community, caring for their island home, and respecting their long history. They strive to maintain a balance between keeping their traditional ways of life and encouraging tourism. After a struggle with polluted waters and diminished sea life, the Sulani Conservationist Society was formed.
Selvadorada
South-southeast of Willow Creek is the large continent of Selvadorada.
Tartosa
From Maxi’s Travel Guide: Romantic sites and scenery have long graced the seaside region of Tartosa, creating the perfect setting for love and matrimonial pursuits. It isn’t uncommon for vacationers and honeymooners alike to return year after year, seeking to re-experience the intimacy of visits past. They say there’s a love story in the making for everyone. Just ask Tartosa’s residents, and they’ll excitedly gossip about local Wedding Industry shenanigans or the area’s love-laced, historical past. But even if a Sim doesn’t find their soulmate here, one thing is for certain…they’re fated to fall in love with the land.