In Finland (and other nordic countries) they mostly don’t have the restriction of ‘trespassing’.

You can roam across and camp on nearly all land, pick berries and mushrooms and catch fish.

The traditional Finnish legal concept of everyman’s right allows free right of access to the land and waterways, and the right to collect natural products such as wild berries and mushrooms, no matter who owns the land. These rights also generally apply to foreign citizens, with certain exceptions related to local boating, fishing and hunting rights.
Everyman’s right means that access to the land is free of charge, and does not require the landowner’s permission. People taking advantage of these rights are nevertheless obliged not to cause any damage or disturbance. Everyman’s right consists of a set of generally accepted traditions that have also been enshrined in various laws and regulations.
Everyman’s right in brief

Everyone may:

walk, ski or cycle freely in the countryside, except in gardens, in the immediate vicinity of people’s homes, and in fields and plantations which could easily be damaged
stay or set up camp temporarily in the countryside, a reasonable distance from homes
pick wild berries, mushrooms and flowers, as long as they are not protected species
fish with a rod and line
row, sail or use a motorboat on waterways, with certain restrictions; swim or wash in inland waters and the sea
walk, ski and fish on frozen lakes, rivers and the sea

You may not:

disturb other people or damage property
disturb breeding birds, or their nests or young
disturb reindeer or game animals
cut down or damage living trees, or collect wood, moss or lichen on other people’s property
light open fires on other people’s property, except in an emergency
disturb the privacy of people’s homes, by camping too near them, or making too much noise, for example
leave litter
drive motor vehicles off road without the landowner’s permission
fish or hunt without the relevant permits