The Bittersweet programme by the Gateway Gardens Trust involved 80 free guided garden visits over two years, around more than 30 gardens in Wales with a range of community groups, schoolchildren and lifelong learners. The themes of the visits and a mobile exhibition were the links between the slave trade and historic gardens, their makers, what they planted, Welsh abolitionists and the wider links with local communities in Wales. Historic gardens provided the starting point, looking at how everyday vegetables and fruits - beans, potatoes, tomatoes etc. - first reached the UK from the Americas. The project also looked at the history of afternoon tea, and the links between sugar, cotton and tea and slavery. The groups reflected on how many industries, grand houses and gardens were built from wealth linked to slavery, such as Cyfarthfa Ironworks in Merthyr and the expansion of the slate industry at Penrhyn Quarry. Early 18th century-style newspapers were produced, aimed at schoolchildren and adults.

Gardens involved included Cardiff’s Bute Park, Swansea’s Singleton Park, the National Botanic Garden in Carmarthen, Gwydir Castle in Llanrwst, Dyffryn Gardens, Portmeirion, Penrhyn Castle, Picton Castle, Dinefwr Park and Castle and Aberglasney Gardens.

The Sites of Memory project was the first research by English Heritage (now Historic England) to provide an overview for the public of the buildings, memorials and grave sites across England that reflects the role of the slave trade in British history, and resistance to it. The project explored the history of Black people in Britain during the 18th and 19th centuries by exploring the stories behind the historic built environment of local streets, buildings and landmarks. The research (by historians Angelina Osborne and S. I. Martin, on behalf of English Heritage) also identified sites associated with the slave trade and plantation wealth, and with the abolitionists who campaigned for an end to slavery. English Heritage also made recommendations for new listings for historic sites that mark the Black presence.