Public access to Ōpārara Basin in Kahurangi National Park has been restored in time for summer.

Work to improve visitor infrastructure at the basin, known for its limestone formations, began in 2020 thanks to $5.7 million from the Provincial Growth Fund.

Up to 15,000 people visit the area each year, and DOC said improvements were needed to keep visitors safe and minimise impact on the unique environment.

Access to the basin was restricted to weekends from May 2022 while McCallums Mill Road was upgraded. The road reopened on December 1.

The first 4.5km of the 16km road has been upgraded, with work on the rest to resume in May 2023.

Ōpārara Arch Track also reopened in December, following construction work, with only Crazy Paving Cave still off limits. The cave is closed until June to protect rare spiders that live there.

DOC wants to see whether the year-long closure improves breeding of the Nelson cave spiders, as only one egg sac has been seen in the cave since 2018.