Marble Garden Zone

You may also be looking for Marble Zone.

Marble Garden Zone is the third zone in Sonic the Hedgehog 3 (or Sonic 3 & Knuckles). The first act contains the most rings out of all the Acts in Sonic the Hedgehog 3 with 636 in total, therefore, a Lightning Shield will prove useful if you want to get the most out of the rings in the level. In this level, the "sinking pools" (from Oil Ocean Zone in Sonic the Hedgehog 2) returns. The mini-boss in the end of act 1 uses a pair of drills to attack the character, both directly and by drilling into the rock above and raining debris on their heads (reminiscent of Dr. Robotnik's own vehicle in the Mystic Cave Zone of Sonic 2).

Sub-boss
The sub-boss of this level is called Tunnelbot, also known as Gakin, who you confront at the end of Act 1. It is one of the easiest sub-bosses in the game. Just like Drill Eggman 2 (Sonic 2), this boss burrows through the ceiling and back. Hit it whenever you can. With Knuckles, there is a rotating spiked platform that you can stand on to compensate for Knuckles' lower jump height.

Boss
The boss of this level is the Drill Mobile, which is fought in an aerial battle over the grassy plains of the zone, or as Knuckles in Sonic 3 & Knuckles in a tunnel. This boss fight is actually the last of a trio of encounters with the Drill Mobile: the first time causes a ramp leading up to a shortcut through a breakable pillar to collapse, and the player must Spin Dash across to make it through. The second encounter causes the ground to rise and the player must race through, negotiating spikes and unhelpful springs before being crushed. Knuckles has a somewhat more difficult version of this section - his path has him dealing with crushing traps, walls that he must open up by Spin Dashing against blue wheels, and by hitting arrow traps three times, just to open a single door. All this whilst keeping ahead of the rising ground.

Trivia

 * When playing as Sonic & Tails, Sonic can stay at the very left of the boss arena while the second player defeats the boss using Tails. When this is done in Sonic 3 alone, it hangs up the game, but it had been fixed in Sonic 3 & Knuckles.
 * This is the only zone in Sonic 3 that does not feature water. Instead, there are mud pits which are far more lethal - Sonic and Tails must constantly jump to remain above the mud. If they sink all the way down to the bottom (which only takes a couple of seconds) they instantly die.
 * Marble Garden's Zone 1 does have the game's largest amount of Special Stage rings - Eight rings scattered along the stage. A good player can get the seven Chaos Emeralds in one Act, by exploring this stage. However, not all rings are accessible by a single way. It is neccessary to die a couple of times in order to explore every corner of the stage.
 * When playing as Knuckles in Sonic 3 & Knuckles there is a way to take the route normally reserved for Sonic and/or Tails in Act 2 (without using debug mode). This can be accomplished by staying on the moving blue platform shortly before the split of the different routes and using it to climb on the non-destructable portion of the wall to the left of the arrow-launching statue (the badniks and destructible wall portions should be destroyed first). By attacking the statue from the wall and re-attaching to the wall after each hit, Knuckles can defeat the statue and access the other route. An interesting side-effect of this is that Knuckles gets to face off against Sonic's version of the Drill Mobile boss at the end of the act and is assisted by Tails (who can be controlled by the second player as with Sonic). This is the only way to have Tails play together with Knuckles. After defeating the boss Tails will not airlift Knuckles into the Carnival Night Zone - he will start from his normal location.