Deepest shaft of the Kremnica gold and silver mining field, located at Kremnické Bane and connected to all three of the district's historic drainage adits.
Anna šachta stands at the roadside in Kremnické Bane, a village some four kilometres north of Kremnica in the Kremnické vrchy mountains of central Slovakia. At 439.2 metres deep it is the deepest shaft in the Kremnica ore field, which has been worked for gold and silver since at least the tenth century and whose formal history as a royal free mining and minting town dates from 17 November 1328. The shaft is intersected by all three of the great drainage adits that successive generations of miners drove to dewater the Kremnica workings: the Horná dedičná štôlňa (Upper Hereditary Adit), the Hlboká (Hornoveská) dedičná štôlňa, and the youngest and deepest, the Hlavná dedičná štôlňa cisára Ferdinanda (Main Hereditary Adit of Emperor Ferdinand), whose total length to Anna šachta reaches 15,481 metres.
The shaft is identified on heritage and tourism sources as a notable technical monument of the Kremnica district.
The Kremnica ore field, within which Anna šachta is sunk, has one of the longest continuous mining histories in central Europe. Gold panning in the streams of the Kremnické vrchy is attested from the tenth century, and organised underground extraction was underway well before the formal grant of royal privileges on 17 November 1328, when King Karol Róbert of Anjou issued a charter conferring on the settlement of Cremnychbana the mining and minting rights of Kutná Hora. In the fourteenth century Kremnica achieved the highest gold output of any town in the Kingdom of Hungary and earned the epithet Zlatá Kremnica — Golden Kremnica.
The Kremnica mint, founded at the same time, has operated continuously ever since. Gold and silver were extracted from hydrothermal veins in the andesite of the Kremnické vrchy, and as surface and near-surface deposits were exhausted, miners were forced progressively deeper, bringing with them the chronic problem of underground flooding. The response was the progressive construction of three successive drainage adits, known as dedičné štôlne, driven horizontally from lower-lying ground into the ore field to carry water away by gravity.
The oldest, the Horná dedičná štôlňa (Mestská dedičná štôlňa), is documented as early as 1385 in what is described as the earliest surviving record of such a mining work in central Europe; its hand-driven length reached 4,280 metres. The second, the Hlboká (Hornoveská) dedičná štôlňa, was begun on 2 October 1519 and, worked intermittently by hand with hammer and moyle, was completed in 1613 after ninety-four years of effort; it runs 7,050 metres and undercuts Anna šachta, forming its fourth drainage horizon. The third and deepest, the Hlavná dedičná štôlňa cisára Ferdinanda — also known as the Svätokrížska adit — was the most ambitious of the three, taking approximately a hundred years to complete; its total length to Anna šachta is 15,481 metres, with 9,461 metres of galleries and crosscuts driven at its level.
It discharges into the river Hron near Žiar nad Hronom. Anna šachta itself, sunk to a depth of 439.2 metres, is the deepest shaft in the Kremnica ore field and the only one connected to all three hereditary adits. It is situated alongside the main road at Kremnické Bane — a village of German colonial origin, first mentioned in 1361 under the name Johanesberg, whose inhabitants provided labour for the Kremnica mines over many centuries.
A bus stop on the Kremnica–Kremnické Bane route bears the name Anna Šachta, confirming the shaft's continued recognition as a local landmark. No surviving headframe or winding house structure at Anna šachta has been identified in the consulted sources, which document intact surface structures at other Kremnica shafts including the Ferdinand shaft and the Ludovík shaft winding tower. The Kremnica mining field as a whole saw its active production wind down during the course of the twentieth century, and the mines are now closed, flooded, or sealed.
The underground hydro-electric station served by the adjacent Štvrtá šachta (Fourth Shaft), launched in 1921 at the level of the Hlavná dedičná štôlňa, continues to operate as part of the Turčekovský vodovod water system.