The Dzukou Valley is a unique geological formation located on the border of Manipur and:

Nagaland
Assam
Mizoram
Myanmar

The correct answer is Nagaland.

The Dzukou Valley is a unique geological formation located on the border of Manipur and Nagaland. It is a high-altitude valley with a temperate climate and a variety of plant and animal life. The valley is also home to a number of traditional villages.

The Dzukou Valley is a popular tourist destination, and is known for its beautiful scenery and its opportunities for hiking, camping, and bird watching.

The other options are incorrect because they are not located on the border of Manipur and Nagaland. Assam is located to the west of Manipur, Mizoram is located to the south, and Myanmar is located to the east.