Teijo's iron began in 1686, when Lorentz Creutz the Younger, governor of Turku and Pori County, obtained the Swedish king's permission to raise an ironworks on the lands of the old Teijo manor. The site made sense for reasons that had nothing to do with scenery: Teijo sits at the head of a sea bay, so ore and iron could move by water; the streams and rivers of the district could be dammed for power; and the seventeenth-century forests here were dense enough to feed a furnace with charcoal. Creutz founded Kirjakkala the same year, a few kilometres inland, and its furnace was completed in 1688 — the eleventh ironworks in Finland. Mathildedal, the third village of the group, followed much later in 1852. The pattern was a division of labour across a landscape: Teijo's blast furnace made the pig iron, which went to the forges at Kirjakkala and later Mathildedal for working into finished goods. At its peak Teijo's furnace was the second largest producer in Finland by volume, and that output had a cost measured in woodland, because a furnace on that scale ran on charcoal, and the charcoal was made by people working the surrounding forests for the works.

Kirjakkala's product list reads like an inventory of eighteenth-century need: ship anchors, spindles for spinning wheels, nails, iron buttons. Nothing decorative, everything necessary. The village that made them was small and built of logs, and while the seventeenth-century factory itself is gone — only stone foundations remain — the nineteenth-century workers' houses were restored to their original appearance and still stand, which makes Kirjakkala one of the more honest places in Finland to see how ironworks families actually lived. Its industrial life ended in 1956, when the last factory operating there burned down. Teijo proper grew into a full ruukkiyhdyskunta, an ironworks community, with roughly seven hundred residents at its height, a primary school from 1869, shops and a post office. The company was the landlord, the employer and the reason the school existed.

Teijo Manor's main building was completed in 1770 in Rococo style, designed by the Turku city architect Christian Friedrich Schröder and raised by Jakob Kijk, then the owner of the works. Pale, symmetrical and entirely at ease with itself, it is the sort of house that makes the social geometry of a ruukki instantly legible — the manor on high ground with its outbuildings, the workers' rows below, the furnace at the water. Bremer's pagoda church went up on a hill nearby some sixty years later. It is easy to read the church as an eccentricity, but the man who commissioned it also owned the houses of the congregation inside it, and Finland's smallest stone church seats a community that had little choice about attending.

Blast-furnace blowing at Teijo stopped in 1908, and the works reinvented itself around the further processing of iron rather than its smelting. Through the first half of the twentieth century Teijo Works became known above all for agricultural tools and machinery — threshing machines especially — and it is fair to say the village played a real part in mechanising Finnish farming in the postwar years. Then came ships. In 1960 Antti Wihuri established a shipyard here on land acquired from Teijo manor, intended as a repair yard for his own fleet; its first job was breaking up the tanker Tupavuori, and the basin had to be enlarged to get the vessel into dry dock. The Wihuri group sold out in 1978. Kari Nurmi founded Oy Western Shipyard Ltd in 1994 to carry the operation forward, mainly on repairs and overhauls, and the yard became a subsidiary of APX-Metalli in 2008; it was renamed Millog Marine & Power Oy in 2022 after joining the Millog marine-and-defense group, though the site is still the same shipyard on Telakkatie. Three hundred and forty years after Creutz's furnace, metal is still being worked at the head of the same bay: a business park in the historic buildings employs over two hundred people in manufacturing.

The forests that were cut for charcoal are now the point of the place. The Finnish state acquired the Teijo woodlands in 1983, and on 1 January 2015 they became Teijo National Park — 34 square kilometres with more than 50 kilometres of marked trail, arranged around four lakes with high rocky shores: Matildanjärvi and Puolakkajärvi to the south, Hamarijärvi and Sahajärvi to the north. Matildanjärvi is one of Metsähallitus's special fishing waters, stocked with rainbow trout and requiring its own permit. There is a small ski area attached to the park, the old blast-furnace building now houses a gallery, and the Finnish Heritage Agency has designated the Teijo and Mathildedal ironworks areas nationally significant built cultural environments. In 2010 Teijo was named village of the year in Southwest Finland. It is a rare thing for a place to be recognised both for the industry it built and for the wilderness it stopped consuming.