Marakuguc Shrine is in Goron City, west of the peak of Death Mountain.
Shrine Location
Marakuguc Shrine is at 1761, 2508, 0437, in the northeastern part of Goron City.
Wheeled Wonders
Use Ultrahand to take the last segment of the nearest bridge and attach it to the uppermost segment of the far side of the bridge, then walk across.
Move the wheeled device in front of the folded bridge. Take the end segment of the bridge and attach it to the back of the wheeled device. Then hit the wheeled device, and it will extend the bridge to the other side. Walk across.
In this area, there are two square metal pieces, each with two wheels. Attach one metal square to the end of the other to create a four-wheeled device. Stand in the middle of it and hit it to start it rolling. It will roll across the lava, taking you to the other side. Hit it again to stop it. Use Ascend to reach the top of the ledge over this area.
Defeat the Soldier Construct, then take the long object off of the floor and lean it up against the column in the corner that has a treasure chest on it. The chest contains a Mighty Construct Bow.
Then attach the long object to the front of the vehicle, with the ends pointing toward the area with the metal balls. Stand on the vehicle and hit it to make it move toward the balls. The long object will push them into the area ahead, activating the floor switch and opening the bars. Go through and check on the dragon ring to get a Light of Blessing and complete the shrine.