June Day, whose house backs onto the sands of Brean Down in Somerset, was left felling horrified when she saw a man pooing in her garden.
Ms Day told the BBC the behaviour was ‘disgusting’ and accused some of the visitors of ‘arrogance’.
She said: ‘People are just defecating on the beach. One man told me he was standing on land that doesn’t belong to me, so he was fine doing it.
‘My husband walked the dog the other day and he stepped over three lots of human faeces with discarded underwear which they’d just left. ‘We’ve got hundreds of people here and there’s no facilities for them.’
A National Trust spokesperson said: ‘We are making opening decisions based on local conditions and urge anyone who wants to visit to check our website before travelling. ‘Where we are able, we will open toilets at our countryside car parks. ‘We will try to publish available toilet facilities on our website, but visitors should be aware that these can change from time to time.’