Arcadia is the living, breathing heart of Rapture. Its lush forests and abundant plant life served to generate the life-sustaining oxygen that the city needed. It was also a tranquil haven for those seeking a respite from the daily rigors of life beneath the surface. Vacationers seeking something more relaxing than the flashing lights of Fort Frolic could find peace and serenity in the lovely Waterfall Grottos, serene Tea Garden and other havens beneath the canopy.
Arcadia was created by the botanical scientists on Ryan's payroll, most notably Julie Langford. Langford created Arcadia by using ADAM to genetically modify and grow the trees. For a time, Arcadia was a park for the citizens of Rapture to unwind and relax in solitude amongst the many trees and hills. Before Rapture collapsed, Andrew Ryan closed Arcadia to all but paying customers (and those who worked there) as he believed that the businesses in that area are entitled to the profit of their products.
The Tea Garden was one of the calmest places in Rapture. Nothing got the betties in the mood better than a night-time stroll in the Arcadia Tea garden. Rolling hills, admirable waterfalls, a calm stream, dim light, and a perfect atmosphere were all part of the Garden's lure. After the fall of Rapture, the Tea Garden's normal customers were kept away by the growing civil strife.
The Tree Farm was the only place where citizens could see trees growing under the ocean. Situated next the entrance gates to Arcadia, it was nigh impossible to miss. However, by the end of the Civil War the area was in disuse and became overgrown, making it nearly inaccessible with a growth of vines keeping the doors shut.
Arcadia Glens was the main hub of Arcadia. From the Glens, visitors could reach the Waterfall grotto, Rolling Hills, the Tea Garden, and the Tree farm. Like the rest of Rapture, it was once a tranquil setting in fairytale woods.
The Waterfall grotto is the most industrious of the Arcadia areas, and much like the rest of Arcadia, has fallen into heavy disuse, its former glory unrecognizable beneath the plant growth, rubble, flood-water, and shadows. The Rosa Gallica was one of the rare plants that bloomed there.
Overlooked by the Research Center, the Rolling Hills was another place for the citizens of Rapture to relax and enjoy the serenity of the verdant park. As the name suggests, the Rolling Hills' common feature is the smooth hilly landscape. Along with the amazing canopy and foliage on show, this made it one of the best places to have a walk in the "woods" of Rapture.
The Research Center itself was the place for all botanical research in Rapture, supervised by Julie Langford. Despite the lockdown of the Bathyspheres by Andrew Ryan, Langford continued to conduct her research here. She installed high security measures in order to keep the Splicers out and to ward off the members of the Saturnine cult.
There is a crawlspace door above and to the right of the U-Invent.
To access this crawlspace (contains corpse, Shotgun, FAK), make a running jump onto the first crate then onto the stacked crates beside it, then onto the ledge above. From there, jump onto the inclined timber and walk across it to the other side, then step onto the level timber next to it and cross back over to the crawlspace.
There is also a storage crate packed with components, which varies with Scrounging.
Go down the steps into the water and make a u-turn.
Use the corpse to knock down the electric wire: components in crate.
Walk along the water and go right, still in the water, at the stairs.
When you see the water ruffle, a Houdini is about to appear:
Set up a Target Dummy if you have one.
Get a couple of pics of Houdini while he attacks the dummy.
It is a good idea to set up Proximity Mines around the entrances before starting the battle as Atlas will send 6 down the pneumo tube, but make sure not to put any in the Big Daddy's path. On harder difficulty settings using cyclone traps is also a good idea. Put cyclone traps in front of the two locked doors; one near the Vita-Chamber and the other next to the Turret in the other room to take out the first attackers. There are also numerous gas tanks and oil barrels around the labs that can be placed in strategic positions to the player's advantage. Placing a Proximity Mine in the corner between the Vita-Chamber and the door in the raised room by the Bot Shutdown Panel will take out the first Houdini Splicer as soon as it appears.
The level name "Arcadia" was inspired by the Latin phrase "Et in Arcadia ego", which translates to "Even in Arcadia I exist" spoken by Death personified. The Utopian vision, Arcadia, is associated with bountiful natural splendor and harmony, so the phrase is a reminder that even in paradise things die, which ironically could be a reference to Rapture itself. Early in development for the level Andrew Ryan was intended to say this phrase just before releasing the poison into the level. The line was later cut, but the name of the level remained.
When the level Arcadia was made, the artists developing it utilized code from a previously removed feature of the game. This feature was originally intended to change lighting, fog, etc. in relation to the pressure of the area the player was in. The artists used the remaining code for the events such as the dying and revival of the trees.