Nestled in Colombia's Sierra Nevada stands Ciudad Perdida, the Lost City. Reach these magical ancient ruins on an extraordinary challenge which will see you making your way through lush jungle, discovering spectacular and unique wildlife and vibrant fauna and flora on an epic journey into the rainforest.

You will explore diverse jungle, swim in beautiful rivers and stand in awe of some of the most breathtaking scenery - what an experience! This is a multi-day trek led by skilled guides. Tough, but truly magical, this challenge will be an adventure you never forget.

Participants of the Colombia Lost City Challenge will need to raise a minimum of £3190 for the Amnesty International UK Charitable UK Trust.

Amnesty International UK works to protect women, men and children wherever justice, freedom, truth and dignity are denied. We defend human rights whenever and wherever they are under threat and bring perpetrators of abuse to justice. We protect individuals at risk, fight for the unjustly imprisoned and prevent torture. We support marginalised groups including women, refugees, LGBTI, and other minority groups.

Some examples of issues they are currently working on include:

"I welcome refugees" - We work to create a fair and effective system for migrants, refugees and asylum seekers in the UK (and abroad). Thanks to months of phone calls, letters, emails, events and MP visits by people up and down the UK, in March we managed to get 131 MP's to sign a bill to bring refugee families together. There's more to be done to give refugees and migrants the protection and support they need and deserve.

Women's rights - Human rights are basic rights that every person on the planet should be entitled to but many are routinely denied to women and girls. Amnesty International UK fights for women's rights across the world, from opposing the ban on women drivers in Saudi Arabia to resisting the Polish authorities attempts to deny women access to safe and legal abortion.

Free Nazanin - we also work on cases of individuals whose human rights have been violated. People like British/Iranian dual national Nazanin Zaghari-Ratcliffe who has been held in Iran for over 2000-days after being found guilty of a crime she didn't commit in a grossly unfair trial. By supporting Amnesty International UK you will join the fight to free Nazanin and reunite her with her family.