Boat trips, circus acts and mini tennis tournaments will be among numerous colourful attractions to celebrate the opening of the Water Rail Way between Lincoln and Boston.
More than 1,000 people are expected to gather on the former railway line beside the River Witham for The Longest Party on April 25.
The event has been organised by sustainable transport charity Sustrans and the Lincolnshire Waterways Partnership with support from various community groups.
Wildlife walks, falconry displays and wood sculpting will all be on offer as actors dressed as navvies and railway workers bring the past to life for visitors.
Sustrans Area Manager Nicola Jones said: “We are delighted to have linked up with so many community groups for this event so we can attract as many people as possible onto the route.
“The Water Rail Way has proved incredibly popular since it opened but we know there must still be hundreds of people living in the towns and villages close by who don’t realise the path is there.
“We often neglect what’s on our own doorstep so this family fun day out will give people the incentive to see what a terrific community facility this path is.”
The final section of the 20-mile route opened in October following four years of development, costing £2million with funding from Lincolnshire Waterways Partnership and the East Midlands Development Agency.
The Longest Party takes place between 11am and 3pm. Refreshments will be available at pubs, cafes and riverside stalls.
For more information about Sustrans, visit: www.sustrans.org.uk