Lake Tana is the largest lake in Ethiopia, stretching approximately 84 kilometres long and 66 kilometres wide, with a maximum depth of 15 metres and sitting at an elevation of 1,788 metres in the north-western Ethiopian Highlands. Fed by the Gilgel Abay, Reb, and Gumara rivers, its surface area ranges from 3,000 to 3,500 square kilometres depending on season and rainfall, and it serves as a principal source of the legendary Blue Nile. The lake is dotted with ancient island monasteries that have sheltered manuscripts, religious relics, and sacred traditions for centuries — many of them still restricted to outsiders. In Expedition Unknown Season 3, Gates crosses Lake Tana by boat alongside biblical investigator Bob Cornuke and Haifa University archaeometallurgist Professor Sariel Shalev, heading toward the remote and closely guarded Tana Kirkos Island, where Ethiopian tradition holds that the Ark of the Covenant rested for some 800 years before being moved to a mainland church. As Gates describes arriving at the lakeshore, he calls it "the largest lake in Ethiopia and source of the legendary Blue Nile" — a journey that feels, in his words, both idyllic and foreboding.
According to Ethiopian tradition, Tana Kirkos Island becomes a repository for sacred artifacts, possibly including those associated with the Ark of the Covenant, following the conversion of the Aksumite Empire to Christianity
Island monasteries on Lake Tana flourish as centers of Ethiopian Orthodox Christianity, preserving manuscripts and religious relics
Lake Tana region nominated as a UNESCO Biosphere Reserve, recognizing its natural and cultural significance
Josh Gates investigates Lake Tana and Tana Kirkos Island in Expedition Unknown S03E12 "The Ark of the Covenant"
On camera, Gates is joined by Professor Sariel Shalev of Haifa University, introduced as a Professor of Archaeology and archaeometallurgist whose specialty is analyzing ancient metal objects to determine how and when they were made. Shalev's role in the episode centers on the possibility of dating metallic artifacts stored on Tana Kirkos Island — relics that, according to Bob Cornuke, arrived on the island alongside the Ark of the Covenant and have never been subjected to scientific testing. Whether that analysis was ultimately carried out, and what it yielded, the transcript does not confirm.
Mainstream historians and archaeologists treat the island monasteries of Lake Tana as genuinely significant repositories of Ethiopian Orthodox Christian heritage, housing illuminated manuscripts, religious paintings, and sacred objects that date back many centuries. Tana Kirkos in particular occupies a prominent place in Ethiopian religious tradition, which holds that the Ark rested there for hundreds of years before being transported to the Church of Our Lady Mary of Zion in Aksum. Scholars of Ethiopian history generally regard these traditions as reflecting the deep integration of Old Testament narrative into Ethiopian national and religious identity — a tradition codified in the medieval royal chronicle known as the Kebra Nagast — rather than as literal accounts of the Ark's physical journey.
The broader question of the Ark of the Covenant's whereabouts remains one of the more earnest debates at the intersection of biblical studies and archaeology. Most mainstream scholars hold that the Ark's fate after the Babylonian destruction of the First Temple in 586 BC is simply unknown, and that claims of its preservation in Ethiopia, while culturally rich, lack corroborating physical evidence. Bob Cornuke, Gates' guide in the episode, is a biblical investigator whose work falls outside academic archaeology, and his conclusions should be understood in that context.
What the episode genuinely contributes is rare on-camera access to the Lake Tana region and the possibility — unconfirmed in the available transcript — of scientific engagement with artifacts that have long been off-limits to outside researchers. Gates is careful to frame the journey as an investigation rather than a revelation, acknowledging at every step that permission to examine anything on the holy island is far from guaranteed.
Lake Tana's surface area fluctuates between approximately 3,000 and 3,500 square kilometres depending on seasonal rainfall — a variation equivalent to hundreds of square kilometres of water appearing and disappearing with the seasons.
The lake sits at an elevation of 1,788 metres (about 5,866 feet) above sea level in the Ethiopian Highlands, making it one of the higher-altitude major lakes on the African continent.
Lake Tana is fed by three rivers — the Gilgel Abay, Reb, and Gumara — and its outflow is regulated by a control weir that manages water flow to the Blue Nile Falls and a hydropower station downstream.
Gates spotted crocodiles in the lake during the boat crossing to Tana Kirkos Island — a detail he noted on camera as persuasive enough to skip the afternoon swim.
Lake Tana itself is generally accessible to visitors, with the lakeside city of Bahir Dar serving as the main gateway and offering boat tours to several island monasteries. Tana Kirkos Island is considered a holy site with significant restrictions on visitor access — travelers should expect that entry may require advance coordination and is not guaranteed. Check current local travel advisories and consult a reputable Ethiopian tour operator before planning a visit.
Bahir Dar, approximately 15–20 kilometres from the southern shore of Lake Tana, is the nearest major city and primary hub for visiting the lake and its island monasteries.
The dry season, roughly October through May, is generally considered the most practical time to visit, offering calmer lake conditions and easier boat travel. The rainy season (June through September) can make lake crossings more challenging and some sites less accessible.
UNESCO Biosphere Reserve (nominated 2015)
Jerusalem
Jerusalem is the origin point of the Ark of the Covenant narrative that Gates investigates through Lake Tana and Tana Kirkos Island, making it a direct thematic companion to the S03E12 episode.
Kingdom of Kush Pyramid Tombs
The Kingdom of Kush Pyramid Tombs represent another African archaeological tradition with deep connections to ancient Near Eastern history and biblical-era civilizations investigated on Expedition Unknown.
Holy Land
The Holy Land appears in multiple Expedition Unknown episodes dealing with biblical archaeology, the same investigative framework that drives Gates' search for the Ark across Ethiopia.
Historical data sourced from Wikipedia