Thais was first city created even before PT3D was in plans. First blocks was placed by Czapol on May 2011 as Project Thais. After some time and few built buildings project was suspended due to miscalculations of floors heights. Later same year project was resumed as Project Thais Reactivation and was successfully finished at end of February 2012. Because of Youtube videos showcasing progression of project, many viewers was interested to help with developing project into next level, when others just wanted to walk through map in Minecraft server. Because of that, on March 2012 minecraft Server of Project Thais was started. Server allows anyone to join (back then you needed to use Hamachi). Players were able to only walk and interact with doors or chests and sightseeing Thais.
Thais is main Free account city on mainland. You can find here all vocations NPC's and many supply shoops. City is located in safe location. Surrounding areas are good hunting spots for new adventurers. You can also find multiple quests around city.
My video from officialy finished Thais from Project Thais: Reactivation, on March 2012