Teachers are used to nasty shocks at the start of the school year, but this week one Israeli school head arrived to find a problem that - literally - dwarfed everything else.
Staff at the Languages and Culture School in Beit Shemesh found that an 8ft wall had been built through the middle of the playground, part of a move to hand half of the building to another school in the city.
The secular school was carved up to provide extra space for Charedi Mishkenot Daat - a nearby strictly-Orthodox school - and is the latest battleground in an ongoing fight between the city's secular and religious populations.
Expectations of tension were so high that guards were in place this week to prevent physical fights.
The space was handed over - without Education Ministry approval - by the city council, headed by the controversial Charedi mayor Moshe Abutbul.
The action struck a raw nerve with the non-Charedi population of a city famous for inter-religious tensions. It comes just six months after Mr Abutbul was re-elected as mayor, following one of the most sectarian political battles ever seen in Israeli local politics - a battle that saw one poll disqualified amid allegations of foul play.
"This has been done illegally and without due process," said Daniel Goldman, a member of the movement Our Beit Shemesh, which fielded the main non-Charedi candidate in the elections.
Mr Goldman, who is originally from Newcastle-upon-Tyne, added that the wall dividing the playground has hurt the feelings of the non-Charedi population, as it implies that Orthodox youngsters would be harmed by seeing their counterparts on the other side.
It is "extremely offensive and extremely insulting to people", he said. Graffiti on the wall declares it a "disgrace to Zionism".
Mr Abutbul's council has defended the classroom reallocation, saying that it is "righting a grave wrong", whereby one school has too much teaching space while another lacks classrooms. But the Education Ministry has condemned the move and turned to the courts for an injunction against the use of the building by the Charedi school, which was granted on Tuesday.