WITNESSING the 'big five' on an African safari, watching humpback whales gleefully leaping out of the ocean, photographing an endangered bird in its natural habitat.
All the above are great, but if catching a glimpse of a Tijuana zebra-donkey isn't on that 'things to do before you die' list then it might as well be void.
Is it a zebra? Is it a donkey? Is it actually a horse with a seriously bad case of mistaken identity?!
Who knows... but the mystical creatures live on the streets of downtown TJ like four-legged gods walking among mere men.
In all seriousness if you're a tourist, no trip to downtown TJ would actually be complete without a picture of one of the hapless sun-baked animals.
And on visiting Avenida Revolucion you’ll be hard-pressed to avoid seeing one – not least being pushed onto one by its owners desperate to grab your cash for a photograph.
I'd heard about them before from Jacks but I didn't actually realise how famous they are. Their existence in the city is woven into the fabric of Tijuana's identity.
The zebra-donkey has become something of a cultural icon here over the decades and people actually travel from far and wide just to see one - even internationally.
Two or three of the animals are paraded around certain spots on a daily basis in front of a cart containing enough colourful sombreros, throws and rugs, to make your eyes water.
Stranger than fiction - behold the zebra donkey
Okay, kids if you don't want to know the truth look away now... the 'zebra donkey' is basically a white donkey which has black stripes painted on it. It's as simple as that.
And people love it so much they have even daubed huge neon pictures of them on shop fronts.
The 'zonkey' expertly presented by Jacks
When I first heard about the animal I thought it was linked to some bizarre legend Tijuana, or indeed Baja California.
But it seems there is no legend.
The truth is in fact stranger than fiction.
A quick scan of the internet states that the bizarre idea to actually paint the stripes on the animals came about in the age of black and white photography so that the animals stood out in the tourists' pictures.
Despite the invention of cameras which could take colour photographs, the animal graffiti stayed.
Personally I question whether back in the day the donkeys got on to their agents demanding more recognition for their role in the tourist trap?
They must be the laughing stock of the farm when they return home after a hard day's work!
What made me laugh even more was the discovery of some websites which are actually claiming that these animals are in fact a "unique breed" - much like the people who try to force you into having your photograph taken with them.
So is it too early to say 'Happy Christmas?!' Well, there you have it!