How do I unmarshal nested XML elements into an array?

My XML contains an array of predefined elements, but I can't pick up the array. Here is the XML structure:

var xml_data = `<Parent>
		           <Val>Hello</Val>
			       <Children>
				      <Child><Val>Hello</Val></Child>
				      <Child><Val>Hello</Val></Child>
				      <Child><Val>Hello</Val></Child>
		           </Children>
	            </Parent>`

Here is the full code and here is the playground link. Running this will pick up Parent.Val, but not Parent.Children.

package main

import (
	"fmt"
	"encoding/xml"
)

func main() {

	container := Parent{}
	err := xml.Unmarshal([]byte(xml_data), &container)

	if err != nil {
		fmt.Println(err)
	} else {
		fmt.Println(container)	
	}
}

var xml_data = `<Parent>
		           <Val>Hello</Val>
			       <Children>
				      <Child><Val>Hello</Val></Child>
				      <Child><Val>Hello</Val></Child>
				      <Child><Val>Hello</Val></Child>
		           </Children>
	            </Parent>`

type Parent struct {
	Val string
	Children []Child
}

type Child struct {
	Val string
}

EDIT: I simplified the problem a bit here. Basically I can't unmarshal any array, not just of predefined structure. Below is the updated work code. In that example, only one item ends up in the container interface.

func main() {

	container := []Child{}
	err := xml.Unmarshal([]byte(xml_data), &container)

	if err != nil {
    	fmt.Println(err)
    } else {
    	fmt.Println(container)	
    }

	/* 
		ONLY ONE CHILD ITEM GETS PICKED UP
    */
}

var xml_data = `
	    	<Child><Val>Hello</Val></Child>
    		<Child><Val>Hello</Val></Child>
    		<Child><Val>Hello</Val></Child>
    	`

type Child struct {
	Val string
}

type Parent struct {
    Val string
    Children []Child  `xml:"Children>Child"`  //Just use the '>'
}

For this kind of nesting, you'll need also a struct for Children element:

package main

import (
	"fmt"
	"encoding/xml"
)

func main() {

	container := Parent{}
	err := xml.Unmarshal([]byte(xml_data), &container)
	
	if err != nil {
		fmt.Println(err)
	} else {
		fmt.Println(container)	
	}
}

var xml_data = `<Parent>
			<Val>Hello</Val>
			<Children>
				<Child><Val>Hello</Val></Child>
				<Child><Val>Hello</Val></Child>
				<Child><Val>Hello</Val></Child>
			</Children>
		</Parent>`

type Parent struct {
	Val string
	Children Children
}

type Children struct {
	Child []Child
}

type Child struct {
	Val string
}

Also pasted here: Go Playground

Note that your code would work (after changing variable name from Children to Child) with this kind of XML structure:

<Parent>
    <Val>Hello</Val>
    <Child><Val>Hello</Val></Child>
    <Child><Val>Hello</Val></Child>
    <Child><Val>Hello</Val></Child>
</Parent>

1: https://play.golang.org/p/-rNryBSq01 "Go Playground"