The International Museum of Slavery in Liverpool will also receive funding for a major redevelopment and the UK's last surviving winter gardens in Great Yarmouth will be saved from permanent loss.
Grants have been awarded to the three environmental projects and two heritage schemes as part of the National Lottery Heritage Fund's Heritage Horizon Awards, which aim to support ambitious, innovative and transformational projects for UK heritage.
Ros Kerslake, chief executive of the National Lottery Heritage Fund, said the awards followed a year in which the organisation had been focused on supporting heritage through the Covid emergency.
She said: "The pandemic has shown us all clearly what matters to us, particularly in relation to nature and climate change.
"This is a major priority for us as an organisation, and three of these projects will be transformational for the green environment.
"All five share qualities of huge ambition, significant collaboration and the prospect of life-changing benefits for people and places deserving of support from the National Lottery."
Culture minister Caroline Dinenage said: "These hugely ambitious, exciting projects are not only protecting and preserving vital local heritage, but are also creating jobs, supporting local communities and helping us to build back better from the pandemic."
The five projects receiving awards are:
Cairngorms 2030: people and nature thriving together, which has received nearly £12.5 million for a scheme involving 45 organisations to tackle the climate and nature crises in the UK's largest national park in the Scottish Highlands.
The scheme, which will be community-led, will include outdoor health programmes and the creation of a nature-based dementia centre and will boost nature through measures such as woodland expansion, peatland restoration, nature-friendly farming and sustainable transport.
Scottish Government minister for environment, biodiversity and land reform Mairi McAllan said with the Cop26 climate talks coming to Glasgow this year, "this project is a great example of community-based action to tackle the twin crises of climate change and biodiversity loss and to improve well-being".
Peatland progress: a new vision for the Fens will receive more than £8 million for a project to store carbon in the peat soils of East Anglia's fens run by The Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire.
Plymouth Sound National Marine Park has received more than £9.58 million for the UK's first national marine park, in an area which hosts the largest naval base in Europe as well as sea grass beds, hundreds of wrecks, and more than 1,000 species of fish and other marine creatures.
The Great Yarmouth Winter Gardens: re-imagining the people's palace scheme is receiving nearly £10 million for the country's only surviving seaside cast iron and glass winter gardens, which are in desperate need of repair and at acute risk of loss.
The International Slavery Museum: igniting ideas and action project is receiving more than £9.9 million to transform and extend the existing collections and galleries of the museum currently located within Liverpool's Maritime Museum.
The museum will work with the local community and those most affected by the legacies of transatlantic and modern slavery, telling the challenging stories of enslavement and celebrating black achievement.