For more than 50 years, Wales's first Welsh-medium secondary has stuck to tradition - everything from science to football is taught in Welsh. And there are no exceptions.
Ysgol Glan Clwyd in St Asaph, Denbighshire, takes huge pride in the fact that nearly all pupils speak Welsh to first-language standard.
That is some feat when you discover that two-thirds of pupils hail from English-speaking homes in this Anglicised area of north Wales.
But the school may soon be unable to meet rising parental demand for good Welsh-medium education.
While critics of the Assembly government's strategy - published last week - have baulked at the cost of building more Welsh-medium schools and providing more resources, the head of Glan Clwyd believes it is a price worth paying.
Above all, Meurig Rees, who is a member of the task group for the Welsh- medium strategy, welcomed proposals to force local authorities to meet parental demand for more schools like his.
"In north Denbighshire, there's a really critical issue because there is high demand, but the Welsh schools are already overcrowded," he said. "I think Welsh-medium schools are the future."
He believes they will continue to thrive and become more "creative, visionary and cost-effective", with e-learning helping them to save costs and share good practice.
Since opening its doors, Glan Clwyd has seen a steady rise in pupil numbers and is likely to be oversubscribed by September.
"The school was new and visionary at the time it opened in 1956," Mr Rees said. "It was definitely in demand, but at the time there were few resources and no training for teachers."
Pupils at the school were the first to take exams in Welsh, through the exam board WJEC, and today every subject is taught in Welsh.
In 2007, Estyn described students' bilingual skills as "outstanding" in all subjects - even those, such as science, that require difficult technical language.
But Mr Rees said most of the school's resources were made by teachers in their spare time.
"There is still a paucity of Welsh-medium resources and the commercial sector is a challenge - nearly everything is in English," he said. "But schools are beginning to work together to share resources and teaching and learning strategies. A lot of co-operation is necessary."
He said Welsh-medium schools were already forging alliances to come up with their own Welsh- language resources for the 14-19 learning pathways initiative.
"If the foundation phase fully takes off, you will get bilingual pupils starting from three years old, but after 14 there is a lack of Welsh- language courses," Mr Rees said.
"Our pupils are truly bilingual - they don't quibble, but it's a travesty that the investment made in helping them become bilingual is wasted when they get to 14 or older."
At Glan Clwyd, one of the biggest commitments is to pupils without any knowledge of Welsh. Each year, about a dozen such pupils start at the school, but after just two years of an intensive immersion course, most are fluent enough to join their peers in mainstream classes.
But Mr Rees is concerned that if Glan Clywd reaches full capacity, this course will be forced to close.
There are also other daily battles he faces. He admits it is a challenge to get the pupils not to speak English in the playground, but he believes most pupils are enthusiastic about the opportunity.
"English culture is a very strong influence on (the pupils) and they are under peer pressure to speak it," he said. "But they also realise that once they step into the school gates, they are in a place where they can improve their Welsh. Praise is vital when they are making an effort to improve."
But Mr Rees also believes every local authority in Wales should listen to what is wanted in that area, which does not necessarily mean a purely Welsh-medium education.
"Some English-medium schools are real beacons because Welsh is everywhere and they use day-to-day simple commands and phrases," he said. "It shows Welsh is a living language, but it's also got to be backed up by effective teaching."
Plain speaking on bilingual issue
TES Cymru receives more postings on its online chatroom about the Welsh language than any other issue. By far the biggest concern is that of trainees wanting to move to Wales but worried they need to speak the language. More recently, there have been pleas for help with translation from non-Welsh speaking primary teachers preparing Welsh lessons.
But there are more serious complaints. Two posters claimed discrimination against their school and colleagues. One said staff meetings were held in Welsh and the head had told them to put up their hand if they were unsure what was being said.
There have also been angry postings from teachers born in Wales but who do not speak Welsh. One said: "I'm all for the Welsh culture and I'm the first one at the rugby flying the Welsh flag, but let's not forget a majority of people who are Welsh do not speak the language."
Plans to boost second-language Welsh were well documented in the draft Welsh-medium education strategy, published by the Assembly government last week.
All trainee teachers will be expected to learn some Welsh and the unpopular second-language Welsh short course will be ditched as the government prepares its full- scale assault on poor standards in second- language Welsh in English-medium schools.
But as parents cry out for more Welsh-medium schools, this sector has challenges of its own to overcome if the government's vision of a truly bilingual Wales is to become a reality.
In 2008, there were 464 primary schools - 30.7 per cent - that were mainly Welsh speaking. There were also 54 secondaries.
However, despite the drive for greater bilingualism, the number of young people fluent in Welsh is dropping. Linguists say this is due in part to the migration of non-Welsh speakers into traditional Welsh-speaking communities, but there have been side effects for schools.
Standards in written Welsh since the late 1990s have dropped dramatically. In response, more emphasis has been placed on written expression and attention to grammar in exam papers produced by the WJEC exam board. But this has led to more students taking their GCSEs and A-levels in English instead.
The government now wants to increase the proportion of Year 2 pupils assessed in Welsh first language from 21 per cent in 2008 to 25 per cent in 2015. It also wants a rise in GCSE Welsh-medium entries from 10 per cent in 2008 to 13 per cent in 2015.
Under the draft strategy, the Assembly government plans to commission teaching and learning resources to meet the needs of the Welsh-medium sector. The government also has to consider children who enter Welsh- medium education late.
Intensive immersion courses are seen as the only way to ensure these pupils have a chance to catch up and don't hold back other pupils.
In the draft strategy, the government cites Ysgol Maes Gormon in Mold as an example of some of the best practice in immersion methods.