Amthuandz is a medium-sized Dwemer ruin currently undergoing excavation, located to the northeast of Tel Muthada.
To reach the ruin, head northeast out of Tel Muthada and stay on the road until you reach Adosi Rothari's Shack. In the northeastern corner of Rothari's farm you should find a set of steps cut into the rock of the mountain. Climb these and you will be in the general area of the ruin, with guards and archaeologists aplenty. According to Corvo Melurus, one of the people in the ruin, the bridge outside Amthuandz used to be the only way through the Boethiah's Spine, making the fortress strategically critical.
Inside, there are several assorted robots and ghosts to deal with, and they guard the usual collection of Dwemer loot. There's a greater than usual concentration of such loot, and the three inhabitants don't mind how much of it you take.