I visited Colombia for the first time with my partner. My trip would've been better if I'd known these 4 things.

• I spent eight days in Colombia, and visited places including Cartagena and Medellín.
• We had an amazing time, but as first-time visitors, we made a few mistakes we wouldn't repeat.
• I should've planned my itinerary differently and taken out much more cash.

I didn't know what to expect when I first visited Colombia, but my eight-day stay in the country was warm, beachy, and something out of a dream.

After browsing dozens of travel blogs and asking friends for their recommendations, my partner and I crafted an itinerary that we hoped would give us a nice mix of relaxation and adventure.

We spent three nights in Cartagena, the country's port city off the Caribbean coast. Then, for another two nights, we unwound in Isla Barú, a beachy peninsula about an hour away from Cartagena.

We concluded our trip with two nights in Medellín, the country's second-largest city, nestled within the Andes Mountain range.

Although I had a fantastic trip, there are definitely things I could've done better when planning our itinerary and exploring the country.

In all 3 cities, I found myself needing more cash

It's standard practice to carry some cash when traveling, but in all three cities I visited, I found myself needing a little more than I had expected.

Although the larger malls and more upscale restaurants accepted credit cards, many smaller shops and street vendors were cash-only.

There were also a few other snags that made us wish we had cash on hand. We took the local train around Colombia, and even though we planned to pay by card, it just so happened that the card reader at one station was down — and the nearby ATM's fee was even higher than our ticket cost.

Bottom line: Next time I travel to South America, I'll take out more cash than I think I'll need.

A day trip to the Rosario Islands would've sufficed

Many travel guides recommend visiting the Rosario Islands, an archipelago of over 20 islands about an hour's boat ride off the coast of Cartagena.

Of the islands, we'd heard that the most popular destinations for tourists include Isla Grande and Isla Barú. We chose the latter, and spent two nights there.

Barú definitely lived up to the hype. The crystal-clear water and white-sand beaches made me feel like I was in paradise, and it was surprisingly just as nice when the weather was overcast.

Not to mention, the seafood was extremely fresh, and it only made our trip better.

Although we enjoyed the downtime, we didn't feel there was enough to do on Barú aside from lounging on the beach. Compared to a few of the other places we visited, there weren't many shops, restaurants, or bars.

As beautiful as it was, we found ourselves a little bored by the end of the stay there. In hindsight, a short day trip would've been the perfect amount of time to explore everything Barú had to offer.

I didn't give myself enough time in Medellín

We didn't properly account for the travel time between our second and final destinations, so unfortunately, we only had two nights in Medellín. It was nowhere near enough time.

In the time we did have here, I visited the Botanical Garden of Medellín and the Museum of Antioquia. I also explored the city through its cable-car system, which offered stunning aerial views of the city's mountainside neighborhoods.

Of the three places I visited, I felt like Medellín had the most to do, and I wish I'd been able to explore spots like the El Castillo Museum and Gardens, the Medellín Museum of Modern Art, Parque Arví, and Mercado Del Río.

At a minimum, I would've loved to spend at least four full days in the city.

Colombia is known for its nature, and I could've definitely done a better job exploring it

Colombia is one of the most biodiverse countries in the world, so seeing the country's natural beauty is a must.

Although we were able to experience the beautiful islands and had a breath of fresh air at the botanical gardens, I would've loved to see more of the country's nature and wildlife.

As I later found out through conversations with taxi drivers and hotel employees, there are so many nature-based "off-the-beaten-path" activities in the country.

Next time I visit, I'm taking a day trip to Guatapé — which supposedly has incredible hiking — and visiting the El Totumo Mud Volcano.

I'd also love to join a coffee-tasting session on a local coffee farm. I can only imagine how good it smells.