Urchin Underpass

"SAFETY NOTICE: Urchin Underpass will be undergoing important construction work. Entry will be strictly forbidden from August 2-5."

- Live from the Squid Research Lab

Urchin Underpass is an online multiplayer stage in Splatoon. It is currently not in the map rotation for online play.

On July 27th, 2015, the official Splatoon Tumblr announced that Urchin Underpass will be going under maintenance between August 2nd and 5th, and access will be strictly forbidden.

Layout
Urchin Underpass features two identical sides that are shaped like large Ls.

Notable Locations

 * Center Plaza – A large, open area in the center of the map.
 * "Secret" Alleys – There are two alleys located near the Center Plaza. They are long, narrow, hidden-away strips of turf that are difficult to access which have two Glass panels.

Splat Zones
The Splat Zone for Urchin Underpass is located in the Center Plaza, specifically encompassing the rectangular lower area covered in grass.

In this game mode, two boxes have been added to the main entryways of the Center Plaza on either side.

Tower Control
In Tower Control, the tower starts in the Center Plaza. It moves straight back towards the enemy territory and climbs up. Then, it moves to the rider's left, climbs back down, and reaches the goal.

Development
Urchin Underpass underwent a series of changes between its development period and release. The pre-release version included many differences, such as:
 * A water tank guarded by a fence could be found in the corner of teams' bases.
 * The raised platform opposite the Spawn Points in teams' bases was accessed by one smaller ramp, included a wooden plank used to swim up through a grated platform, and did not provide access to the Center Plaza.
 * The lowest area in teams' bases was much larger.
 * When leaving a team's Spawn Point and heading left, the first ramp encountered was not present. Instead, players could go around the raised portion on either side. This raised portion was split into three differently-sized platforms, and a window was not present in this location.
 * The walls of the Secret Alleys were concrete, not glass.
 * When entering the Center Plaza from the main entrance, a small fence acting as a grated barrier was present on players' immediate left.
 * The ramped platforms allowing players to jump to the other side of the Center Plaza were directly opposite each other.
 * The middle area in the Center Plaza was slightly smaller.
 * The grated walkways outside the Secret Alleys in the Center Plaza were extended.
 * The concrete walls used to swim into the Secret Alleys from the Center Plaza were covered in artwork of a tanuki and a fox, respectively.
 * Urchin Underpass will be unavailable from August 3rd through August 5th, leading up to a change in the August 6th, 2015 update. A blueprint of changes appears the update will remove the two trees, widen and extend the back alleys including more access to the middle area, add a little more ground area near the ramps in the middle aread, and add or modify something to the middle area.

See also changes from E3 2014 to release 2015.

Update
On July 27th, 2015, the official Splatoon Tumblr announced that Urchin Underpass would be undergoing maintenance between August 2nd and 5th. They released an image showing the original map scribbled on, allowing fans to see what about the stage would be changed. Many features were altered, including:
 * The trees near each team's base were moved to the center of the stage.
 * The secret alleys were extended and pushed further away from the central area.
 * The grated walkways protruding from the secret alleys were removed.
 * The ramps leading into the central area were made so that they only took up half of the available space. The other half became flat turf.

Tips

 * There is a large amount of turf behind the spawn point on either side. Be sure to claim it.
 * While the most obvious entrance to the secret alleys is through the gated ramp, it's also possible to paint the walls at the exits in the center plaza and swim up to the platform there. This is useful for sneakily getting into enemy territory or taking out bothersome snipers in these locations.
 * Above the main exit of each team's spawn, there are low rafters. This is a good place to put a sprinkler, as it covers a sizable area from above and many players will not think to look up there.

Trivia

 * An early version of this stage was first revealed at E3 2014 and was the only playable map at the time.
 * A night variant of this stage exists in Octo Valley in the mission Unwelcome Flying Object.