Seems to be mixed on the national parks here are some of the more positive / welcoming ones:
Visitor destinations are cautiously preparing to welcome day-trippers after the government relaxed its advice on the lockdown
The South Downs National Park, which covers almost 630 square miles of Hampshire, West Sussex and East Sussex, said that visitors were welcome provided they followed social-distancing guidance.
Many beaches across England are accessible although there are no lifeguards on the 240 that the RNLI normally patrols.
The National Trust, which maintains 780 miles of coastline and 500 properties, opened smaller car parks from Wednesday and will open more next week. The trust
said that “while our houses and gardens remain closed . . . we’re opening some car parks so you can get out into much-needed green space”.
The Yorkshire Dales and North York Moors national parks will reopen many car parks and some public lavatories from this weekend. The Yorkshire Dales will be using a traffic light system to help visitors to identify how busy they are.
Sale Water Park, a 152-acre area of countryside and parkland in Greater Manchester, has reopened its car park, allowing visitors.
Jersey Zoo is allowing members to visit, with people asked to book online to secure an allocated time slot. A maximum of 500 visitors are permitted to enter each day.