One of their guides is Parking, Lincoln.
Lincoln, The Lawn Car Park LN1 3BU. £9.50 24 hours, £4.50 (6pm-8am). This car park is in the historic uphill area, opposite the castle, 5 mins from Cathedral. Great pubs and restaurants. No dedicated MoHo spaces but plenty around the edges where you can stick your bum over the grass. No problem sleeping overnight but no "camping" behaviour. No facilities. Check for "events" such as steam punk or 1940's weekends when the car park can get very busy.
Take a walk down Steep Hill to the High Street, walk back up and then state "Lincolnshire is all flat"
This member live 10 miles away and often use it for a night out as it's cheaper and more convenient than a taxi.