Crypts of the Founders refer to special collectible Documents found in Rise of the Tomb Raider.
There are five total Crypts of the Founders documents in the game.
Kokkos, The Astronomer
A prophet must have his followers. Kokkos of Nicea was one of the Prophet's first. Branded a heretic in his home city, Kokkos joined the pilgrimage north. His knowledge of the stars helped guide the way. It is said that Kokkos and the Prophet would sit for hours under the stars debating the nature of the universe and man's fraught place within it.
For the Prophet, he built an Orrery of planets and stars, so that even during the dark winter, he might gaze upon the night sky.
Lara's Thoughts
The city of Kitezh wasn't built by the Prophet alone... He drew the best and brightest to his fold.
Damien, The Prophet's Forge
Cities are not built on plans alone. There must be material and there must be someone who knows how to build. Damien was that man. They say he could muster brick from nothing more than a handful of dirt and a tinderbox. They say his craftmanship was divinely inspired. It is his hands that gave form to the architect's dreams.
Lara's Thoughts
Building a city like Kitezh would take many skills and talents. The Prophet lauded every contribution.
Aurora, The Physician
The road to Kitezh was long and hard. Infirmity, illness, and injury abounded. Aurora was a believer trained in the ways of Hippocrates and the great Roman healers. It is because of her that so many survived the journey to Kitezh; it is her legacy that knowledge of healing continues to be passed down among believers.
Lara's Thoughts
In order to build the new city, the Prophet and his followers had first to survive the long journey.
Rivkah, The Architect
Rivkah joined the Prophet because her husband, a Rus nobleman, was a believer. When he died on the journey north, she stayed with the Prophet, pondering what her place was amongst the believers.
When she saw the valley, she knew she had found her purpose. She dreamed what Kitezh could be. She laid those dreams out to be built. It is because of Rivkah that Kitezh became not just beautiful, but livable.
Lara's Thoughts
A great City needs a great architect... and the Prophet found his among the Rus...
Valentinus, The Time Keeper
After the city was built, the first generation of followers started out upon it. One among them, a man named Valentinus, had spent his whole life devoted to the study of time and its passage. The Prophet sought him out in the crowd and asked him what he thought of the city. Valentinus said he felt it was a blessed place. That time would move slowly there and that Kitezh would last for generations untold.
The Prophet smiled for he knew that he had made a home where his people might be safe.
Lara's Thoughts
Kitezh was home to artists, philosophers, and more. Who knows what it might have become...