Honeymoon in Spain 10/10 - Off the beaten path

For a truely unique honeymoon location, I would suggest Castillo de Emporada, www.castelldemporda.com near Girona. Fantastic location and accommodations. You will need to make reservations well in advanced. An ancient castle, it has been brought to a high level of modern standards, and will be a great find for you. I was there a couple of years ago with a group and had a great time.

Another possibility, Zamora - NW of Madrid, the renaissance masterpiece of Europe...and off the beaten tourist traffic way.

Madrid would be a great choice as well. These three suggestions offer completely different aspects of Spain.

Sorry to disagree with your travel philosophy...but it's akin to telling foreign visitors not to visiting Washington because they they won't get a "feel" for what the United States is all about.
Madrid is one of the great cities of Europe, with 4.5 million people living there, most of them Spanish who might object to your suggestion that you can't get a "feel" for this city because of tourists. There are all sorts of places to go where you won't find a tourist in sight. But it is a hub for tourists simply because of all the sights to see and things to do....that's why it's a popular place to visit.
Ditto with cities like Toledo, Segovia, Avila, Sevilla, and Granada. Hundreds of thousands of tourists (Spanish, European, and American) visit those places every year to try to discover Spain. But their presence doesn't "taint" their charms...it's because of those charms that people go in the first place. We're not talking about some sort of "plastic" world like Disneyland or Las Vegas....we're talking about the real thing....centuries of history, before Europeans ever set eyes on North America.
Try doing a bit more research on Spanish history to understand what it is you're seeking in the first place. The country is a unique meld of Christian, Jewish, and Moorish influences, strongly affected by nearly 800 years under Islamic rule and the subsequent Christan reconquest. This permeates life in Spain at all levels, from how people vote, to how they dance and sing in Andalucia.
Yes, you'll be stuck with fellow tourists much of the time. But look around you. The woman selling lottery tickets in the Puerta del Sol....the cabbie sitting outside the Giralda in Sevilla....the waiter at the cafe in the Plaza Nueva in Granada....these are all real Spanish people. If you want the REAL Spanish experience, get involved with them. Ask them about what it means to be Spanish. Don't worry about the presence of tourists....after all, you'll be one of them!

BTW...if you want the "Spanish experience," don't spend a lot of time in Barcelona....

If you really, really want to see a part of Spain that nobody seems to know about, check out the north coast. It doesn't get good until you're a bit west of Bilbao (and skip Santander), but if you stick to the coast roads instead of the freeway you'll have a great time.

Santillana is a great place to spend one night and the cave paintings at Altamira are nearby. You might also want to duck up into the Picos de Europa National Park.

Go all the way to Coruna and on out to the end of the world at Fisterra and then cut back to Santiago where you'll encounter your first tourists on the whole trip.

From there you can continue south to the Douro River (Spain - Portugal border) and work your way east on either side (I'd pick the Portugese side), then head to Salamanca. From there it's Avila, Segovia, Toledo(touristy but great) and on into Madrid to finish up.

The whole trip is only seven or eight hundred miles. You could do it in a week, but ten days would be better (not counting time in Madrid).

Oh, yeah ..... what Norm said. Skip Barcelona.

I'll make it a third... See Madrid to see Spain, see Barcelona to see Europe.

I like both Ed and Norm's advice.

For a Honeymoon I'd be inlcined to eithe linger in the white hill towns in the south... or... linger in San Sebastien in the north... but that's a tough call...

If you have a car and the time, here are some off the beaten path places I would suggestion IN ADDITION TO the touristy sights. To really get a feel for these places, stay overnight at least.
Consuegra...a small town south of Madrid, site of several of the old "Don Quixote" style windmills. A nice town center, but not a lot of nightlife....a quiet town without a tourist to be seen.
Talavera de la Reina...a growing city southwest of Madrid (you can reach it by train in about 90 minutes) that's become very popular with young families who can't afford to live in Madrid. The site of a relatively new university, it's a very young city in terms of population, with lots of good restaurants and bars. You find lots of chances to chat up Spanish people there.
Badajoz...southwest of Madrid near the Portuguese border. Another university town with a large population of young people, so it's pretty lively. The city has pust a lot of work into sprucing up it's old town center....it's very attractive. Dominated by a huge Arab-built fortress that was also the site of a rather bloody seige during the Spanish War of Independence.
La Alberca....a medieval village caught in time west of Madrid in the Sierra de Francia mountains. Once one of the poorest regions of Spain, its residents lived in poverty until a visit from King Alfonso and his subsequent declaration of it as a national heritage center in the 1930's. Located on the pilgrimage trail from Sevilla to Santiago de Compostela, it is very popular with Spanish families in the summer, unknown by other tourists, and slumps sleepily back into its small-town self after tourist season is over.

Like other European destinations, timing is important in Spain. Summer may be too hot and crowded - best months are April and May or June and September. Spain's capital, Madrid, because of its size and vitality, might be the country's single most rewarding destination if you're really serious about Spanish culture, especially if you speak the language. But for a quick shot of classic Spanish charm with lots of wine and sunshine, the best option might be to head south first. Or if you're looking for really great food, spectacular scenery and serious surf, head north instead. You should also bear in mind that in many ways Barcelona is as foreign to Madrid as Lisbon is to both. And although flamenco-postcard Andalusia and trendy Catalonia may be the country's prime tourist magnets, Central Spain makes up for its lack of "costas" with a truly formidable array of medieval castles (the nation's heartland is called Castilla, meaning "land of castles") spread thick amid impressive snow-capped mountains and historic gem-towns such as Cáceres, Guadalupe, Segovia, Avila, Cuenca, Salamanca or Toledo to name a few.

Fernando: Welcome to the Helpline! Your insights, as a resident of Spain, are especially helpful to those of us here.