For hikes:
A pair of ‘all-terrain’ shoes, which must be waterproof and suitable for walking through water and muddy patches
A waterproof jacket (or rain cape)
A pair of jeans or comfortable trousers for walking
Layered tops following the three-layer principle, suited to the season and weather: short- and long-sleeved T-shirts | Cardigan or jumper | Jacket or fleece
A small rucksack
Cap or hat & sun cream in summer | Hat and gloves in winter
For other activities:
Comfortable shoes for after the walk / Casual clothing for physical activities / Swimsuit / Warm loungewear for the evenings.
Other
Personal first-aid kit if you are on medication | Writing materials