The Fun Forest Mini ticket starts at 20 euro, and the 10-euro accompanying adult is compulsory rather than an extra

Fun Forest runs four climbing parks, in Amsterdam, Almere, Rotterdam and Venlo, and prints all four price lists on the same page. The smallest tier is the Mini: 24 euro in Amsterdam, 20 in Almere and Rotterdam, for two hours across two courses from 110 centimetres tall. That is not what you pay. One line further down the same page, Mini Begeleider (18+) at 10 euro is marked Verplicht bij aankoop Mini-ticket, compulsory with a Mini ticket. So one six-year-old in Amsterdam costs 34 euro rather than 24, and 30 rather than 20 in Almere and Rotterdam. The gap between locations is not only in that tier: the same children's ticket buys six courses in one park, five in another and four in the third, so the price per course ranks the three parks in a different order from the price on the ticket.

• The Mini ticket across the locations: 24 euro in Amsterdam, 20 in Almere and 20 in Rotterdam, each from 110 centimetres, advised from age 6, two hours over two courses. (source 1)
• The Mini accompanying adult, 18 and over and from 150 centimetres, is 10 euro, marked compulsory with a Mini ticket, and the park advises one adult per four minis. (source 1)
• The children's ticket, from 130 centimetres, advised from age 8, three hours: 31 euro over six courses in Amsterdam, 27 over five in Almere, 27 over four in Rotterdam, with all three stating that climbing alongside an adult unlocks two more. (source 1)
• The youth and adult ticket, from 150 centimetres, advised from 12, three hours: 33 euro over nine courses to 15 metres in Amsterdam, 29 over eight to 18 metres in Almere, 29 over seven to 15 metres in Rotterdam. (source 1)
• Amsterdam also has an Explorer tier from age 3 at an advised 90 centimetres for 19 euro, where the site states a parent is required to walk alongside. (source 2)

The first sum is what actually leaves your account: the Mini price plus 10.00 times the number of accompanying adults. One adult with one Mini is 24 plus 10, so 34.00 euro in Amsterdam and 20 plus 10, so 30.00, in Almere and Rotterdam. The escort fee counts adults, not children, and the park advises one adult per four minis, so four children together come to 4 times 24 plus 10, which is 106.00 euro, or 26.50 a child. The more children, the thinner that 10 euro spreads, which makes this the tier to book with other families rather than alone.

The second sum is the price of a single course: ticket price divided by the courses you may climb. On the children's ticket Amsterdam is 31 over 6, or 5.17 euro, Almere is 27 over 5, or 5.40, and Rotterdam is 27 over 4, or 6.75. The result runs against intuition: the most expensive ticket is the cheapest per course, and the cheapest ticket is the dearest. All three sites add that climbing with an adult unlocks two more courses, so buying the adult ticket alongside changes the denominator again.

The third point decides whether either sum applies at all: height. The four thresholds are 90, 110, 130 and 150 centimetres, and the ages beside them are only advice. A tall seven-year-old who reaches 130 gets the children's tier; a shorter nine-year-old does not. The park measures centimetres, not birthdays. Much of the Netherlands works this way, the same convention that sizes children's clothes by height in centimetres, and it is rarely mentioned at the point of sale.

Hokimi field note: measure with a tape before you leave and write the number down. The thresholds that catch people out are 130 and 150, where a centimetre or two is the difference between five courses and nine, and the ticket is already bought. The Amsterdam Explorer tier also states that a parent must walk alongside, so in practice that tier is always two tickets.

Where

Four Fun Forest climbing parks: Amsterdam, Almere, Rotterdam and Venlo

When

Two hours on the Mini and Explorer tiers, three hours on the children's and adult tickets

Price

Mini 20 to 24 euro, children 27 to 31, adults 29 to 33, accompanying adult 10

Ages

Four height bands at 90, 110, 130 and 150 centimetres; the ages are advisory

Note

On the Mini tier the accompanying adult ticket is compulsory, not an optional extra