This is my favorite hidden arena in ESPN NBA 2K5, it's an arena themed after Sega's mascot, Sonic the Hedgehog! As it features Sonic himself in center court! It also features a few other simple graphics on the court design as well, it isn't much but it's really cool, this arena first appeared in the original NBA 2K on Dreamcast and ESPN NBA 2K5 would be the last appearance as Sega would sell the series to Take Two Interactive in 2005.
To unlock this arena, simply create a custom team with the Hedgehogs logo. (The logo with Sonic in it)
While this is the home arena for any team using the Sonic the Hedgehog logo, you actually don't have to make a Hedgehogs logo custom team the home team, you can use this arena with any team as the home team, it's super fun to have 2 real NBA teams play against each other in this arena! A little bit ago, I did a matchup of the Houston Rockets vs. the Atlanta Hawks in this cool Sonic the Hedgehog themed arena!
I just love how Sega put cameos of their famous mascot Sonic the Hedgehog in the Sega era NBA 2Ks!