The second thing is distance.
The city, one of the fastest growing in the world, is already - says chatty tour guide Ali Kierat - bigger than the states of Kuwait and Qatar combined; a jaw-dropping 120km by 100km.
Riyadh is the capital of Saudi Arabia, defined by the authoritative Lonely Planet as one of the most difficult places on Earth to visit - “the last frontier of tourism”.
For some, Saudi is the birthplace of Islam and the custodian of the religion’s two most sacred sites; for others, it’s just the world’s richest reserve of oil.
Riyadh blends both effortlessly, but a trip to Al Masmak, the Hollywoodesque fort in the centre of the city and a pilgrimage to the hi-tech national museum in the King Abdul Aziz historical centre, not only provides context, but reveals gems often lost to outsiders.
The story of modern-day Saudi Arabia begins at Al Masmak, the restored 1865 mud brick fort where a young prince won back his family’s honour on January 14, 1902 after being exiled to the desert.
Abdul Aziz and his men slew the governor who lived there, forced his men to surrender and then, as King Abdul Aziz bin Saud (known in Western history books as Ibn Saud), forged a nation among the other tribes and clans in the Arabian peninsula, including taking over control of the two holy mosques in Mecca and Medina.
Saudi Arabia was recognised as a country in 1932 and oil was discovered in 1938.
The rest is history. Much of that history can be felt in the rooms of the fort, starting at the door where Abdul Aziz’s spear point is still wedged in the jamb to the cannon used until 1970 to let residents of Riyadh know when to start fasting and when to break during the holy month of Ramadaan.
Then there’s the incredible photographic collection taken by St John Philby, King Abdul Aziz’s adviser, and father of Britain’s most infamous cold war spy, Kim Philby.
From Al Masmak, there’s a short stroll through Deera Square - infamous for being the venue of public beheadings, it’s better known as “Chop Chop Square” - to Al-Zall Souq, a typical tourist market, reminiscent of Istanbul’s Grand Bazaar.
It’s a tourist’s delight, long on traditional Arab kit from the red-checked shemaghs or ghutras, the camel-halter rope that keeps it in place, thobes, gowns, curved daggers and swords for the men; bejewelled abayas and hijabs for the women; oud, the traditional Arab incense; Arab coffee pots and carpets.
The truth is though you can pick up much the same in the neighbouring United Arab Emirates - perhaps, perish the heresy, even cheaper.
The real jewel lies in the National Museum - a stone’s throw from the Murabba Palace where Abdul Aziz moved in 1938 from Al Masmak.
The National Museum is a hi-tech, no-expense-spared trip through the history of Saudi Arabia, which means the history of Islam.
The key showpiece for the next seven weeks is the Roads of Arabia exhibition that has finally come home after being on show at the Louvre in Paris and the Carnegie museums in Pittsburgh, among others.
It’s a wonderful snapshot of the Arabian peninsula which takes the visitor all the way back to pre-Islamic history to the Bronze Age, to Babylonian times and from there to the incense routes and finally to the pilgrims’ routes to Mecca.
Some of the artefacts are breathtaking such as the old door to the ka’aba in Mecca - perhaps one of the only opportunities a non-Muslim will get to see something of this nature.
The National Museum is a place you can lose yourself in for hours.
Afterwards, take a taxi out to the Diriyah and wander about the neighbouring Al Bujairi district, that is like any upmarket modern entertainment mall in any South African city, minus the bars and cinemas, of course.
Diriyah itself is off limits, except for the walls which are lit up at night, while restoration beyond them creates what will be the world’s biggest open-air museum, says Kierat.
It’s an intriguing mix of the new and an old that has been made new; typical of Saudi Arabia today, a deeply conservative country in a region beset by crises, many bloody and existential, as it looks to its past to chart a way through the future.
Long off limits to all but essential business visitors, travelling to the kingdom doesn’t just provide a very real primer to understanding the fault lines in the peninsula and the broader Middle East that ultimately affect us all, it’s also a fascinating glimpse into a unique history that goes back to the beginning of time.