IT'S NOT Provence. It's not even Norfolk. But the heady, uplifting and refreshing scent of lavender and the blanket of mauve across acres and acres of countryside, as far as you can see and beyond, might make everyone think that's where you are when you post your photos on social media. Tell them, instead, that it's actually deepest Castilla-La Mancha – the bit of Spain everyone escapes from in summer because it doesn't have a beach; the central plains rarely remarked upon for their natural beauty – flat, earthy fields that remind you of East Anglia during a drought but without the trees, a region too often overlooked for being anything other than the hinterland you cross to get to Madrid.

July in Castilla-La Mancha and Castilla y León, and specifically the former's province of Guadalajara and, within it, the rural Alcarria district, is a time and a place you need to experience together at least once in a lifetime. It's an area where 80% of cultivated land is used to grow lavender, a crop that has multiplied fivefold in the last decade in both regions and which, it is hoped, will help halt the rural exodus suffered by many inland regions a long way from the nearest large town or city. The village of Almadrones, just over an hour from Madrid, has a population of just 30, but is home to 300 hectares (741 acres) of lavender fields – literally 10 hectares, or 25 acres, for every inhabitant. In fact, between Almadrones, Cogollor and Brihuega in the Alcarria district, over 2,000 hectares (4,942 acres) of land is coated with this powerfully-aromatic purple flowering cereal.

Probably one of the most 'Instagrammable' sights in Spain in summer, by day or, better still, at sunset.

Haute couture in Brihuega

Nowadays, the village of Brihuega in the province of Guadalajara is home to 10% of the world's lavender crop – only Provence, China and Bulgaria, in that order, produce more. And although this plant was already native to the area, its proliferation owes a great deal to one of Spain's most élite fashion houses: Emilio Valeros, the then technical director of Loewe – whose €600 knitted tops and €800 handbags are not exactly within everyone's price range – taught locals 40 years ago how to distill lavender and turn it into essential oils. Fast-forward to 2019 and the local distillery in Brihuega processes around two tonnes of lavender a day.

Lavender essential oil is excellent for skin repair and is often used in anti-ageing cream, as well as in soap and perfume; lavender sachets in your sock draw will give you fresh-smelling feet; lavender oil on your pillow helps give you quality, relaxing sleep; it's used in shampoo, conditioner, fabric conditioner, body lotion, bubble bath, shower gel...in fact, next time you're in a supermarket or cosmetics shop, just do a rough count of how many products use this plant and you'll get an idea of how crucial it is to the rural economy in central Spain.

And of course, among clients who buy Guadalajara lavender in about half the world's countries, its main one continues to be Loewe.

Go it alone or book a guided tour

Being so close to Madrid – barely an hour by road and with buses from the capital's Méndez Álvaro station several times a day to Brihuega run by the coach company Autocares Samar, S.A. - thousands of Spanish and foreign holidaymakers and residents make a day trip of it; once in Brihuega itself, the best way to find this purple paradise is by car, but if you opt to use public transport, you can book a guided tour of the lavender fields through the town's tourist information office (Plaza del Coso, number 14).

These generally run between 19.00 and 20.30, the perfect time to enjoy the aroma and scenery without the punishing heat of the middle of the day (although it's a dry heat in Guadalajara, being several hours from the nearest coast) and also about the right time to catch the sunset over the fields for the perfect, romantic photograph.

Naturally, with so many flowers needing pollinating (and honey made from them), only one way for pollination to be carried out and only one species able to do it, you'll be sharing the fields with a high number of bees. But don't let them put you off – unless you torment them, they won't sting, and they have so much to do in so many crops that they're completely focused on the flowers they're drinking from and don't tend to mix with humans wandering between them.

Guided tours run daily, and many include a trip to the distillery to see how the crop is turned into essential oil. You can book these via Turismobrihuega.com, by emailing the town hall's tourism department at turismo@aytobrihuega.com, calling 949 280 442 or 949 340 030, or check out private companies such as Britur.

A day trip may set you back as little as €3, depending upon what it includes.

If you're visiting in your own or a hired car, you can find the fields by heading down the CM-2005 for about four or five kilometres (keep going a little further if you want to avoid the crowds) or along the GU-925 for about 10 kilometres (ditto about the crowds). Both areas have car parks set up and landowners allow visitors to walk right into the fields.

The latter has a small kiosk selling products made from local lavender – perfume, room-spray, air-fresheners, soap, sponges, essential oils and so on – although you'll find shops in the distillery and all over the Alcarria area offering a vast range of lavender-based souvenirs.

Fiestas, pop concerts, parties...

You'll need to plan your trip carefully, almost to the day – the lavender crop in the province of Guadalajara does not last forever. It begins to bloom at its best in late spring, and the harvest starts between mid-July and early August – you don't want to get there when it's already been cut down and they're ploughing the fields for next year's batch. July is the best month to see it at its full potential, and if you're heading in that direction, you may as well try to coincide your trip with the annual Lavender Festival.

Every July 19 and 20, the district spills out onto the streets to celebrate its beautiful crop – a huge gala dinner-dance, usually with the catering by a top chef (this year's was Dani García) is held in the open air and anyone can join in; various activities in and out of the actual lavender fields, mostly in and around the village of Malacuera a few kilometres out of Brihuega, take place round the clock for two days; gourmet catering stands are set up in the streets, and on each night, a nationally-famous pop or rock act – normally some prominent top 40 artist or band – gives an al fresco concert.

This year, Luz Casal performed on Friday and Ketama on Saturday – another reason why planning is essential for this unique trip, since tickets tend to sell out for the concerts months in advance, not least because buses are run from Madrid for each night.

When arranging your summer lavender tour, pack something white to wear – although not compulsory, the Brihuega Lavender Festival dress code of all-white attire makes sense, since when fiesta-goers mingle in the middle of the fields, the colour contrast makes for the best photos. Also, of course, white is the most comfortable tone in summer, because it does not absorb the heat.

You may well still catch the fields aglow with lilac and pumping out natural perfume if you hurry up there now – or blank out this weekend in your diary for 2020 and start planning.

Brihuega and surrounding villages have plenty of delightful rural hotels oozing with character, so you needn't rush to make it a day or evening trip from Madrid – the Hotel Spa Niwa in Brihuega is perfect for relaxation and the Princesa Elima, also a restaurant, is designed like a Moroccan riyadh. Here as well as the Peña Bermeja restaurant next to the castle, with its perfect outdoor summer terrace, come highly recommended for dining out.

Photographs 1 and 3: El Rincón de Sele (@elrincondesele) on Instagram and Twitter

Photographs 2, 4 and 5: Festival de la Lavanda de Brihuega (Festivaldelalavanda.com)