Egypt has opened King Sneferu’s 4,600-year-old “bent” pyramid to the public.

The 101m-high structure, in the Dahshur royal necropolis, just south of Cairo, is one of two built for Sneferu, the pharaoh who founded the Fourth Dynasty.

Tourists will be allowed inside the ancient structure after archaeologists found “hidden tombs” containing mummies, masks and tools.

The pyramid’s appearance is unusual, with the first 49m, which have largely kept their smooth limestone casing, built at a steep 54-degree angle before tapering off in the top section.

People can now clamber down a narrow 79m tunnel from a raised entrance on the pyramid’s northern face to reach two chambers deep inside the ancient structure.

Egyptian ‘bent’ pyramid dating back 4,600 years opens to public Show all 10 1 /10 Egyptian ‘bent’ pyramid dating back 4,600 years opens to public Egyptian ‘bent’ pyramid dating back 4,600 years opens to public A man walks through a passage into the bent pyramid of Sneferu, which was reopened after restoration work, in Dahshur, south of Cairo, Egypt, 13 July, 2019. Mohamed Abd El Ghany/REUTERS Egyptian ‘bent’ pyramid dating back 4,600 years opens to public King Sneferu’s 4,600-year-old 'bent' pyramid in the ancient royal necropolis of Dahshur, in Egypt, has opened to the public. A man walks in front of one the Bent pyramid satellites, in the ancient royal necropolis of Dahshur on the west bank of the Nile River, south of the capital Cairo, on 13 July, 2019. Mohamed el-Shahed/AFP/Getty Images Egyptian ‘bent’ pyramid dating back 4,600 years opens to public A sarcophagus on display near the bent pyramid. Mohamed el-Shahed/AFP/Getty Images Egyptian ‘bent’ pyramid dating back 4,600 years opens to public Egyptian minister of antiquities Khaled El-Enany speaks in front of the bent pyramid of Sneferu. Mohamed Hossam/EPA Egyptian ‘bent’ pyramid dating back 4,600 years opens to public Egyptian tourist police stand with recently-discovered artefacts at the Memphis necropolis during an event opening the bent pyramid to tourists. Maya Alleruzzo/AP Egyptian ‘bent’ pyramid dating back 4,600 years opens to public A sarcophagus on display near the bent pyramid. Mohamed el-Shahed/AFP/Getty Images Egyptian ‘bent’ pyramid dating back 4,600 years opens to public A man walks through a passage in the bent pyramid. Mohamed el-Shahed/AFP/Getty Images Egyptian ‘bent’ pyramid dating back 4,600 years opens to public The bent pyramid of King Sneferu. Mohamed el-Shahed/AFP/Getty Images Egyptian ‘bent’ pyramid dating back 4,600 years opens to public A man brushes off dust from a sarcophagus on display near the bent pyramid. Mohamed el-Shahed/AFP/Getty Images Egyptian ‘bent’ pyramid dating back 4,600 years opens to public A sarcophagus on display near the bent pyramid. Mohamed el-Shahed/AFP/Getty Images

They will also be able to enter an adjoining 18m “side pyramid”, possibly built for Sneferu’s wife Hetepheres, opened for the first time since its excavation in 1956.

As they opened the pyramids to the public on Saturday, archaeologists showed late-period mummies, masks, tools and coffins discovered during excavations that began near the Dahshur pyramids last year.

Mostafa Waziri, secretary general of Egypt’s Supreme Council of Antiquities, said: “When we were taking those objects out, we found ... A very rich area of hidden tombs.”

The pyramid marked a key step in the evolution of pyramid construction. Its angular shape contrasts with the straight sides of Sneferu’s Red Pyramid just to the north – the first of ancient Egypt’s fully-formed pyramids and the next step towards the Great Pyramid of Giza.

Architects changed the angle when cracks started appearing in the structure, according to Mr Waziri.

Mohamed Shiha, director of the Dahshur site, said: “Sneferu lived a very long time ... the architects wanted to reach the complete shape, the pyramid shape.

“Exactly where he was buried, we are not sure of that. Maybe in this pyramid, who knows.”

Authorities are looking to promote tourism at Dahshur, located about 17 miles south of central Cairo.

The site, which lies in the open desert, attracts just a trickle of visitors and is currently free of the touts and bustle of Giza.

The promotion of Dahshur is part of a wider push to boost tourism, an important source of foreign revenue for Egypt that dipped steeply after the country’s 2011 uprising before gradually recovering.

Archaeologists also unveiled the nearby tomb of Sa Eset, a supervisor of pyramids in the Middle Kingdom, which has been closed since its excavation in 1894 and contains finely preserved hieroglyphic funerary texts.

Foreign ambassadors invited to attend the archaeological announcements were led into the tight spaces of the tomb, which is not expected to be opened to the public for another two years.