Quad

 is an Expert Map in Bloons TD 6. It was released on Version 6.0, along with the map Moon Landing, as well as the Mortar Monkey.

Overview
Quad appears to be a park with stone paths on a green scenery. Bloons spawn at the same time and exit on the four floral trusses. Bloons follow the paths around the stage until they reach their opposite angled entrance, creating a frantic scene for the player as bloons floods through the park. The four paths are connected to each other by four removable floral trusses (all four trusses block line of sight and cost $1500 to be removed). Upon removing, a bulldozer piloted by a monkey appears and bulldozes it. In the middle, a pond with lily pads and reeds resides that allows water monkeys to be placed, each corner of the paths has a bush, there are four decorative ribbons above the stone paths and the outside has a vast, green field for towers.

Trivia

 * This is the second Expert Track in BTD6 to be released in an update, after Dark Castle.
 * Ever since November 2018, the entire BTD6 community has been dedicated to beating CHIMPS on Quad, similar to that for #Ouch prior to Version 5.0 during September 2018. The first non-bugged solution was officially resolved on version 10.1 using The Biggest One. Link. After The Biggest One nerf, Quad CHIMPS was resolved on Version 11.0 with Grandmaster Ninja and even Black Bordered with no glitches. Gold Border Link, Black Border Link.
 * Prior to 9.0, this map was unable to be completed in normal CHIMPS mode without glitches, alongside Muddy Puddles before its spawn order was altered. This means it could be the hardest track in the game.
 * In 8.0, Quad C.H.I.M.P.S. was beaten by exploiting a glitch using Shell Shock Mortar Monkeys, Druids of the Jungle, and Striker Jones level 9+. This was patched for 8.1, however.
 * As of now, Quad is the only non-Beginner Map and only non-Snow/Ice Map to use the soundtrack "Winter Nights", although the Beginner Map Candy Falls now also uses this soundtrack.
 * Quad is the first map in the game to contain the letter "Q". The second to do so is Quiet Street.