The age gate is the confirmation screen at the entrance to this site; the house deals only with adults aged 21 or over, clients and therapists alike.
A border officer checks a passport before a traveller enters the country. This site asks a simpler question before anyone enters it: is the visitor 21 or older? Continuing past that screen is the visitor's own declaration that they are. The exact text of that screen sits on the age verification page.
Many sites draw the line lower. The house draws it at 21 for everyone, in both directions: no client under 21 is accepted, and none of the forty-five therapists is younger than that. A higher line leaves less room for guesswork near the margin, and it fits the people who actually book from rooms around the airport: business travellers, crews on a rest period, passengers on a long connection, residents with an evening to spare before a flight.
Travel is often arranged by someone other than the traveller. An assistant books the hotel; a partner plans a surprise for a birthday spent in transit. Either may write to the office, but the threshold applies to the person the therapist actually meets. A booking intended for anyone under 21 is declined, and the decision is not debated.
If something in a thread leaves the office unsure about age, it declines rather than guesses. That is applied evenly and carries no accusation.
The gate has a second, quieter use. Lounge computers and hotel business corners are full of shared screens, and a phone passed across a table to show a boarding pass can land on whatever tab was last open. A screen at the entrance gives anyone who arrived here by accident a clean moment to close the page. What the site keeps about visitors is explained on the privacy page.
One hour EUR 180 through to eight hours at EUR 1,250. Forty to sixty minutes anywhere in the centre; the Schiphol airport hotels by arrangement.