Portland's disused quarry attracts the adonis blue butterfly
Long celebrated for its limestone, Portland also has a reputation for an array of butterflies, which enjoy the shelter of the now disused quarry.
Spring is a "perfect" time of year to see these insects.
Joy Wallis, Dorset Wildlife Trust's people and wildlife coordinator, said: "The weather has warmed up and their food plants are flowering, so they come out to lay their eggs."
Adonis and common blues are the species most likely to be seen here.
The site also attracts small blue, chalkhill blue, small copper and small heath varieties.
Joy said: "This abandoned quarry is within the Isle of Purbeck Site of Special Scientific Interest (SSSI).
"The site, unworked for more than 100 years, is now a fragile habitat that has allowed wildlife to reassert itself in the old derelict workings.
Bird's foot trefoil plants are 'good caterpillar food'
"It's brilliant for butterflies as they enjoy the many wildflowers and plants, which have re-established themselves over time on the shorter grassland.
"The adonis likes horseshoe vetch [a plant with yellow flowers and oblong leaves], while the common blue feed on bird's foot trefoil [similar to clover with yellow and orange flowers] - this is particularly good caterpillar food - and the small blue prefer kidney vetch [a perennial plant with round flowerheads and a woolly brown covering].
"The low grass at the quarry means that they are also visible for attracting mates and because it's not overgrown the butterflies can also enjoy the sheltered suntraps."
Joy Wallis will lead a butterfly walk at King Barrow Quarries on Wednesday 9 June from 1100 until 1300.
It costs £1 per person to take part and you are advised to wear sturdy footwear.
The walk is not suitable for those with limited mobility.
Participants should meet at the name stone, on Yeates Road, just off the A354, on Portland.
For more information contact Joy on 01305 264620.