Isberga Nature Reserve at Norrö lies in an undulating landscape formed by the ice sheet. It has a unique steppe flora including the rare Hairy Milk-vetch. From this area there is an extensive view across the Östergötland plain.
At Norrö there are hillocks, ridges and water-filled depressions, a landscape that was shaped by the melting ice sheet 10 000 years ago.
Large blocks of ice were left in the depressions and before these melted they were covered in gravel and morain thus forming the present hillocks and ridges. The gently rolling landscape at Norrö is used both as arable and pasture-land.
In the spring the hills are dappled yellow by Cowslips, Bulbous Buttercups and Spring Cinquefoil with a sprinkling of purple provided by Pasque Flowers. The less common Northern Androsace, a relative of the Cowslip, can be found flowering in the south.
Around midsummer the rare yellow Hairy Milk-vetch is in flower at Isberga. This has only been found in a further five places on the Swedish mainland, all being on the plains of Östergötland. Small Scabious, Five-leaved Vetch, Spiked Veronica and Tufted Milkwort also flower on the hills of Norrö.
The reserve consists of 24 hectares and is privately owned.