The richest of the islanders
Sifnos had gold and silver in the ground, and in the sixth century BC it was, by Herodotus's account, doing better out of it than anyone else in the Cyclades.
…the Siphnians were at this time very prosperous and the richest of the islanders, because of the gold and silver mines on the island. They were so wealthy that the treasure dedicated by them at Delphi, which is as rich as any there, was made from a tenth of their income; and they divided among themselves each year's income.
That is Godley's translation of 1920. Notice what it describes: a tenth to the god at Delphi — a treasury as rich as any there — and the remaining nine tenths shared out among the islanders every year. Not a treasury, not a war chest. Divided annually, among themselves.
The oracle
They asked Delphi whether the good years would last. The answer:
When the prytaneum on Siphnus becomes white And white-browed the market, then indeed a shrewd man is wanted Beware a wooden force and a red herald.
And then Herodotus adds one flat sentence that turns the whole thing into a trap: at this time the market-place and town-hall of Siphnus were adorned with Parian marble.
They had just faced their own public buildings in white marble. They had done it with the money. The condition in the prophecy was not something that might happen to them one day — it was the thing they had spent their wealth on, and it was already finished.
The wooden force was ships, and in those days ships were painted with vermilion. The Samians arrived, asked for ten talents, were refused, went through the countryside, beat the Siphnians in a battle, and left with a hundred.
Why the mines flooded, depending on who you ask
Pausanias tells it as a moral, and he is very direct about the mechanism:
The Siphnians too made a treasury, the reason being as follows. Their island contained gold mines, and the god ordered them to pay a tithe of the revenues to Delphi. So they built the treasury, and continued to pay the tithe until greed made them omit the tribute, when the sea flooded their mines and hid them from sight.
Jones and Ormerod, 1918. The mines drowned because the island stopped paying.
Modern scholarship gives a different account and does not contradict the flood itself. Some of the galleries were driven out below sea level, and water is what happens when you do that. The majority, well inland, were not flooded at all — they were simply worked out. The silver ran to an end, which is what silver does.
Both explanations point at exactly the same ground, and neither has ever had to give way to the other, because they are answering different questions. One says why it stopped. The other says what it meant.
The part of the island you will not get to
The mining country is the northern arc — Agios Sostis, Agios Sylivestros, Vorini, Kapsalos, Xeroxylo — with the gold ground separately, near Ai Yianni at Faros, Apokofto and Aspro Pyrgo.
None of that is on the walks from Apollonia. The tracks go to Kastro, to Faros, to Vathy, to Kamares. The mines are somewhere else on the island, and this essay is not going to pretend otherwise or send anybody looking.
What is there, for the record, is remarkable. Ancient galleries at Agios Sostis run below the present sea level and stand in water; two of them have been recorded in three dimensions by laser scanning. Whether any gallery can lawfully or safely be entered has not been established — this office does not know, and viewed from outside and entered are very different things. So take this as something true about the island rather than as somewhere to go.
Richest, or worthless
Herodotus says richest of the islanders.
Strabo, writing later, records a proverb. Looking across from Kimolos you can see Siphnos, and people said Siphnian knuckle-bone — meaning a thing of no value at all.
Nobody in antiquity reconciled those. The island is remembered in one text as the wealthiest in the Aegean and in another as a byword for worthlessness, and both sentences came down to us intact. That disagreement is better than either half of it, and you should not expect this essay to settle it.
Where the oracle stops being a text
Here is the good part, and it needs one careful sentence to hold it up.
Sifnos says that Kastro is the city Herodotus meant. The municipality identifies the site as the ancient city that flourished in the sixth century BC, with a prytaneion, a large temple, a theatre, and grand marble public buildings in what it calls the white agora.
Read that against the oracle again. When the prytaneum on Siphnos becomes white, and white-browed the market. The island has put both of those words on a specific hillside you can walk up.
That identification is Sifnos's own. Whether excavation confirms a prytaneion and an agora at those exact points has not been established, and this essay is not telling you it has. But it is a genuinely interesting thing for a place to say about itself — that the warning was about here, about these stones — and the walk up from Apollonia takes you into it either way.
At the top there are the remains of the ancient acropolis, including a wall of Sifnian marble that the municipality describes as the only surviving marble wall of its era in the Cyclades. Ancient columns turn up built into later house walls. Roman sarcophagi sit in the alleys. Kastro is not a site with a ruin in it; it is a village that has been made out of its own earlier versions, and nobody ever stopped to sort the layers out.
And the older one
On the hill above Vathy is the acropolis of Agios Andreas, which is older than all of this — a Mycenaean wall and a street plan, on a plateau of about ten thousand square metres, excavated across four decades by Varvara Philippaki and then Christina Televantou.
It is open every day except Mondays, half past eight to three. Your Monday is the twenty-first, so that is the day it will not be there for you, and the Tuesday is a departure morning with a transfer at ten to eleven.
What the island is actually about
A place that got rich out of the rock, spent the proceeds on making itself visibly, publicly white, and was told in advance and in writing that this was the dangerous part.
You can walk up into the vocabulary of that warning on an afternoon from Apollonia. You cannot get to the mines. And the two accounts of why the mines ended — a god's bookkeeping and an exhausted seam — have been sitting side by side for two thousand years without either of them winning.