Deuteronomy 1:2 (ESV)

2 It is eleven days’ journey from Horeb by the way of Mount Seir to Kadesh-barnea.

Horeb is another name for Mount Sinai, where the Lord made his covenant with the generation that preceded the one now standing with him in Moab. It takes eleven days to travel from Horeb to Kadesh-barnea, which was located in the wilderness of Paran (Num. 13:26), near the border of the Promised Land.

The function of this verse in its context is unclear, though it is possible that it relates to the names in verse 1, some of which may have been located in the area of the Sinai Peninsula