The iconic Trollpikken before vandals destroyed it.

A penis-shaped rock formation in southern Norway is up again after the popular tourist attraction was found badly damaged last month.

Workers put back more than 12 tons of heavy rock that broke off the Trollpikken formation two weeks ago.

They used iron wedges and concrete to reattach the broken promontory after winching it up inside 10-metre-high scaffolding.

Joggers discovered drilling holes in the rock south of Stavanger that suggested it was deliberately vandalised.

More than 226,000 kroner ($NZ47,613) was donated online to repair it.

However, broadcaster NRK says visitors need to wait at least a week for the formation to be fully set before climbing on it.

No arrests have been made for the alleged vandalism.