Our ambassadors are in the northern Persian city of Caswin, about 50 miles from the Caspian Sea, and near their lodgings is a tree full of nails and ribbons. A saint who once performed miracles is buried under the tree, and a holy man at the site collects alms and offerings from people who come for healing from toothaches, fevers, and other diseases.

The healing is not free, of course, and the alms collected by the holy man encourage impostors to set up shop at other trees where no saints are buried.

The Germans leave Caswin on January 20, 1638. Fifteen miles to the west, they spend the night in the small town of Achibaba, which, we are told, was named after an old man who lived there in the time of Sheikh Sefi, the mystic Sufi master whose name was taken by the Safavid dynasty.

Allah performed a miracle for the old man and his wife – who were then near 100 years old – by reviving what Olearius calls “the heat of younger years” and giving them a son.

The modern name of the town is Aghababa, but some sources refer to it as Aqbaba. Aside from census data and weather reports, there is very little information about the town, but one nugget makes up for all that is missing. To find it, we have to travel forward in time to the year 1921. For in 1921, the little town of Aqbaba served as the launchpad for a mostly-bloodless coup by Col. Reza Shah Pahlavi and the Persian Cossack Brigade that ended the reign of the Qajar dynasty, which had ruled the country since 1785.

Achibaba, Olearius tells us, is at “the foot of the mountain” – the mountain being part of the Alborz range between Caswin and the Caspian Sea – and the road passes through fruitful country where the people of Caswin graze their cows on plentiful, excellent good grass.

On January 23, the road leads through a forest of olive trees to a narrow passage, anciently called the Fauces Hyrcaniae, that leads to Kilan province and thence to the Caspian.

On the last day of January, the khan of Kurab greets the Germans with 100 horsemen, accompanies them to their lodgings, and sends them a gift of four wild boars.