Vamos por donde empieza la ciclovía.

It can be understood either way depending on context, but in everyday speech it often means let’s go.

• Vamos is literally we go / we are going.
• But Spanish very commonly uses the first-person plural present tense to make a suggestion:
  • Vamos. = Let’s go.
  • Comemos aquí. = Let’s eat here.

So in this sentence, Vamos por donde empieza la ciclovía can naturally mean something like:

• Let’s go by where the bike lane starts.
• or We’re going by where the bike lane starts.

Context tells you which one is intended.

Por is used because the sentence is talking about the route or way you go, not just the destination.

A very useful basic contrast is:

• ir a = to go to a place
• ir por = to go through / along / by way of a place or route

So:

• Vamos a donde empieza la ciclovía = We’re going to where the bike lane starts.
• Vamos por donde empieza la ciclovía = We’re going through/by way of where the bike lane starts.

Here, por donde suggests the path taken.

Por donde often means through where, by where, or along where, depending on context.

In this sentence, it introduces the route:

• por donde empieza la ciclovía

This means something like:

• by where the bike lane starts
• through the place where the bike lane starts
• along the area where the bike lane begins

It is very common in directions and route descriptions.

Because this is not a direct or indirect question. It is a relative word introducing a clause.

Compare:

• ¿Dónde empieza la ciclovía? = Where does the bike lane start?
  • accent: dónde
• Vamos por donde empieza la ciclovía. = We’re going by where the bike lane starts.
  • no accent: donde

A simple rule:

• dónde = interrogative/exclamatory forms
• donde = relative forms

Because the subject is la ciclovía, which is singular.

Break it down:

• la ciclovía = the bike lane / bike path
• empieza = starts / begins

So:

• la ciclovía empieza = the bike lane starts

If the subject were plural, then the verb would be plural too:

• las ciclovías empiezan = the bike lanes start

In much of Latin America, ciclovía usually means a bike lane, bike path, or cycling route, depending on the place.

The exact English translation can vary because usage varies by country and city:

• a painted bike lane on a street
• a separated bike path
• sometimes even a route reserved for cyclists

So the best translation depends on context, but bike lane or bike path is usually fine for learners.

It has an accent because the stress falls on the í: ci-clo-ví-a.

Without getting too technical, the accent helps show that -ía is pronounced as two syllables here, not merged into one.

So it is pronounced roughly like:

• ci-clo-VEE-a

This accent is part of the normal spelling of the word.

Spanish often uses the definite article where English may or may not use the.

Here, la ciclovía means:

• the bike lane
• or sometimes the bike path

The article can sound natural because the speaker has a specific bike lane in mind, or because it is understood from the situation.

Spanish generally uses articles more often than English, so la ciclovía sounds completely normal.

Yes, but it changes the meaning slightly.

• Vamos donde empieza la ciclovía = We’re going to where the bike lane starts.
• Vamos por donde empieza la ciclovía = We’re going by / through / along where the bike lane starts.

So:

• donde alone points more to the destination
• por donde points more to the route

Both are grammatical, but they are not exactly the same.

Sometimes yes, but not with exactly the same meaning as this sentence.

If you want to emphasize movement toward a destination, Spanish can use:

• adonde
• a donde

For example:

• Vamos adonde empieza la ciclovía.
• Vamos a donde empieza la ciclovía.

These mean We’re going to where the bike lane starts.

But your original sentence has por donde, which is about going through/by that area, not simply to it.

Yes, in most cases.

• empieza comes from empezar
• comienza comes from comenzar

Both mean starts / begins.

So you could also say:

• Vamos por donde comienza la ciclovía.

That sounds natural too. In everyday speech, empezar is often a bit more common, but both are standard.

It is a relative clause of place.

The word donde introduces a clause that describes a location:

• donde empieza la ciclovía = where the bike lane starts

Then that whole clause works with por:

• por donde empieza la ciclovía = through/by where the bike lane starts

So instead of naming a place directly, the speaker identifies it by describing it.

Yes, it sounds natural, especially in the context of giving directions or choosing a route.

It could be used in situations like:

• deciding how to walk or bike somewhere
• telling someone which way to go
• describing a route on a map

The most important nuance is that por makes it sound like the speaker is talking about the way you go, not just the endpoint.